Carla/source/modules/juce_gui_basics/widgets/juce_TextEditor.cpp

/*
  ==============================================================================

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

// a word or space that can't be broken down any further
struct TextAtom
{
    //==============================================================================
    String atomText;
    float width;
    int numChars;

    //==============================================================================
    bool isWhitespace() const noexcept       { return CharacterFunctions::isWhitespace (atomText[0]); }
    bool isNewLine() const noexcept          { return atomText[0] == '\r' || atomText[0] == '\n'; }

    String getText (juce_wchar passwordCharacter) const
    {
        if (passwordCharacter == 0)
            return atomText;

        return String::repeatedString (String::charToString (passwordCharacter),
                                       atomText.length());
    }

    String getTrimmedText (const juce_wchar passwordCharacter) const
    {
        if (passwordCharacter == 0)
            return atomText.substring (0, numChars);

        if (isNewLine())
            return {};

        return String::repeatedString (String::charToString (passwordCharacter), numChars);
    }

    JUCE_LEAK_DETECTOR (TextAtom)
};

//==============================================================================
// a run of text with a single font and colour
class TextEditor::UniformTextSection
{
public:
    UniformTextSection (const String& text, const Font& f, Colour col, juce_wchar passwordCharToUse)
        : font (f), colour (col), passwordChar (passwordCharToUse)
    {
        initialiseAtoms (text);
    }

    UniformTextSection (const UniformTextSection&) = default;
    UniformTextSection (UniformTextSection&&) = default;

    UniformTextSection& operator= (const UniformTextSection&) = delete;

    void append (UniformTextSection& other)
    {
        if (! other.atoms.isEmpty())
        {
            int i = 0;

            if (! atoms.isEmpty())
            {
                auto& lastAtom = atoms.getReference (atoms.size() - 1);

                if (! CharacterFunctions::isWhitespace (lastAtom.atomText.getLastCharacter()))
                {
                    auto& first = other.atoms.getReference(0);

                    if (! CharacterFunctions::isWhitespace (first.atomText[0]))
                    {
                        lastAtom.atomText += first.atomText;
                        lastAtom.numChars = (uint16) (lastAtom.numChars + first.numChars);
                        lastAtom.width = font.getStringWidthFloat (lastAtom.getText (passwordChar));
                        ++i;
                    }
                }
            }

            atoms.ensureStorageAllocated (atoms.size() + other.atoms.size() - i);

            while (i < other.atoms.size())
            {
                atoms.add (other.atoms.getReference(i));
                ++i;
            }
        }
    }

    UniformTextSection* split (int indexToBreakAt)
    {
        auto* section2 = new UniformTextSection ({}, font, colour, passwordChar);
        int index = 0;

        for (int i = 0; i < atoms.size(); ++i)
        {
            auto& atom = atoms.getReference(i);
            auto nextIndex = index + atom.numChars;

            if (index == indexToBreakAt)
            {
                for (int j = i; j < atoms.size(); ++j)
                    section2->atoms.add (atoms.getUnchecked (j));

                atoms.removeRange (i, atoms.size());
                break;
            }

            if (indexToBreakAt >= index && indexToBreakAt < nextIndex)
            {
                TextAtom secondAtom;
                secondAtom.atomText = atom.atomText.substring (indexToBreakAt - index);
                secondAtom.width = font.getStringWidthFloat (secondAtom.getText (passwordChar));
                secondAtom.numChars = (uint16) secondAtom.atomText.length();

                section2->atoms.add (secondAtom);

                atom.atomText = atom.atomText.substring (0, indexToBreakAt - index);
                atom.width = font.getStringWidthFloat (atom.getText (passwordChar));
                atom.numChars = (uint16) (indexToBreakAt - index);

                for (int j = i + 1; j < atoms.size(); ++j)
                    section2->atoms.add (atoms.getUnchecked (j));

                atoms.removeRange (i + 1, atoms.size());
                break;
            }

            index = nextIndex;
        }

        return section2;
    }

    void appendAllText (MemoryOutputStream& mo) const
    {
        for (auto& atom : atoms)
            mo << atom.atomText;
    }

    void appendSubstring (MemoryOutputStream& mo, Range<int> range) const
    {
        int index = 0;

        for (auto& atom : atoms)
        {
            auto nextIndex = index + atom.numChars;

            if (range.getStart() < nextIndex)
            {
                if (range.getEnd() <= index)
                    break;

                auto r = (range - index).getIntersectionWith ({ 0, (int) atom.numChars });

                if (! r.isEmpty())
                    mo << atom.atomText.substring (r.getStart(), r.getEnd());
            }

            index = nextIndex;
        }
    }

    int getTotalLength() const noexcept
    {
        int total = 0;

        for (auto& atom : atoms)
            total += atom.numChars;

        return total;
    }

    void setFont (const Font& newFont, const juce_wchar passwordCharToUse)
    {
        if (font != newFont || passwordChar != passwordCharToUse)
        {
            font = newFont;
            passwordChar = passwordCharToUse;

            for (auto& atom : atoms)
                atom.width = newFont.getStringWidthFloat (atom.getText (passwordChar));
        }
    }

    //==============================================================================
    Font font;
    Colour colour;
    Array<TextAtom> atoms;
    juce_wchar passwordChar;

private:
    void initialiseAtoms (const String& textToParse)
    {
        auto text = textToParse.getCharPointer();

        while (! text.isEmpty())
        {
            size_t numChars = 0;
            auto start = text;

            // create a whitespace atom unless it starts with non-ws
            if (text.isWhitespace() && *text != '\r' && *text != '\n')
            {
                do
                {
                    ++text;
                    ++numChars;
                }
                while (text.isWhitespace() && *text != '\r' && *text != '\n');
            }
            else
            {
                if (*text == '\r')
                {
                    ++text;
                    ++numChars;

                    if (*text == '\n')
                    {
                        ++start;
                        ++text;
                    }
                }
                else if (*text == '\n')
                {
                    ++text;
                    ++numChars;
                }
                else
                {
                    while (! (text.isEmpty() || text.isWhitespace()))
                    {
                        ++text;
                        ++numChars;
                    }
                }
            }

            TextAtom atom;
            atom.atomText = String (start, numChars);
            atom.width = font.getStringWidthFloat (atom.getText (passwordChar));
            atom.numChars = (uint16) numChars;
            atoms.add (atom);
        }
    }

    JUCE_LEAK_DETECTOR (UniformTextSection)
};

//==============================================================================
struct TextEditor::Iterator
{
    Iterator (const TextEditor& ed)
      : sections (ed.sections),
        justification (ed.justification),
        justificationWidth (ed.getJustificationWidth()),
        wordWrapWidth (ed.getWordWrapWidth()),
        passwordCharacter (ed.passwordCharacter),
        lineSpacing (ed.lineSpacing)
    {
        jassert (wordWrapWidth > 0);

        if (! sections.isEmpty())
        {
            currentSection = sections.getUnchecked (sectionIndex);

            if (currentSection != nullptr)
                beginNewLine();
        }
    }

    Iterator (const Iterator&) = default;
    Iterator& operator= (const Iterator&) = delete;

    //==============================================================================
    bool next()
    {
        if (atom == &tempAtom)
        {
            auto numRemaining = tempAtom.atomText.length() - tempAtom.numChars;

            if (numRemaining > 0)
            {
                tempAtom.atomText = tempAtom.atomText.substring (tempAtom.numChars);

                if (tempAtom.numChars > 0)
                    lineY += lineHeight * lineSpacing;

                indexInText += tempAtom.numChars;

                GlyphArrangement g;
                g.addLineOfText (currentSection->font, atom->getText (passwordCharacter), 0.0f, 0.0f);

                int split;
                for (split = 0; split < g.getNumGlyphs(); ++split)
                    if (shouldWrap (g.getGlyph (split).getRight()))
                        break;

                if (split > 0 && split <= numRemaining)
                {
                    tempAtom.numChars = (uint16) split;
                    tempAtom.width = g.getGlyph (split - 1).getRight();
                    atomX = getJustificationOffset (tempAtom.width);
                    atomRight = atomX + tempAtom.width;
                    return true;
                }
            }
        }

        if (sectionIndex >= sections.size())
        {
            moveToEndOfLastAtom();
            return false;
        }

        bool forceNewLine = false;

        if (atomIndex >= currentSection->atoms.size() - 1)
        {
            if (atomIndex >= currentSection->atoms.size())
            {
                if (++sectionIndex >= sections.size())
                {
                    moveToEndOfLastAtom();
                    return false;
                }

                atomIndex = 0;
                currentSection = sections.getUnchecked (sectionIndex);
            }
            else
            {
                auto& lastAtom = currentSection->atoms.getReference (atomIndex);

                if (! lastAtom.isWhitespace())
                {
                    // handle the case where the last atom in a section is actually part of the same
                    // word as the first atom of the next section...
                    float right = atomRight + lastAtom.width;
                    float lineHeight2 = lineHeight;
                    float maxDescent2 = maxDescent;

                    for (int section = sectionIndex + 1; section < sections.size(); ++section)
                    {
                        auto* s = sections.getUnchecked (section);

                        if (s->atoms.size() == 0)
                            break;

                        auto& nextAtom = s->atoms.getReference (0);

                        if (nextAtom.isWhitespace())
                            break;

                        right += nextAtom.width;

                        lineHeight2 = jmax (lineHeight2, s->font.getHeight());
                        maxDescent2 = jmax (maxDescent2, s->font.getDescent());

                        if (shouldWrap (right))
                        {
                            lineHeight = lineHeight2;
                            maxDescent = maxDescent2;

                            forceNewLine = true;
                            break;
                        }

                        if (s->atoms.size() > 1)
                            break;
                    }
                }
            }
        }

        if (atom != nullptr)
        {
            atomX = atomRight;
            indexInText += atom->numChars;

            if (atom->isNewLine())
                beginNewLine();
        }

        atom = &(currentSection->atoms.getReference (atomIndex));
        atomRight = atomX + atom->width;
        ++atomIndex;

        if (shouldWrap (atomRight) || forceNewLine)
        {
            if (atom->isWhitespace())
            {
                // leave whitespace at the end of a line, but truncate it to avoid scrolling
                atomRight = jmin (atomRight, wordWrapWidth);
            }
            else
            {
                if (shouldWrap (atom->width))  // atom too big to fit on a line, so break it up..
                {
                    tempAtom = *atom;
                    tempAtom.width = 0;
                    tempAtom.numChars = 0;
                    atom = &tempAtom;

                    if (atomX > justificationOffset)
                        beginNewLine();

                    return next();
                }

                beginNewLine();
                atomX = justificationOffset;
                atomRight = atomX + atom->width;
                return true;
            }
        }

        return true;
    }

    void beginNewLine()
    {
        lineY += lineHeight * lineSpacing;
        float lineWidth = 0;

        auto tempSectionIndex = sectionIndex;
        auto tempAtomIndex = atomIndex;
        auto* section = sections.getUnchecked (tempSectionIndex);

        lineHeight = section->font.getHeight();
        maxDescent = section->font.getDescent();

        float nextLineWidth = (atom != nullptr) ? atom->width : 0.0f;

        while (! shouldWrap (nextLineWidth))
        {
            lineWidth = nextLineWidth;

            if (tempSectionIndex >= sections.size())
                break;

            bool checkSize = false;

            if (tempAtomIndex >= section->atoms.size())
            {
                if (++tempSectionIndex >= sections.size())
                    break;

                tempAtomIndex = 0;
                section = sections.getUnchecked (tempSectionIndex);
                checkSize = true;
            }

            if (! isPositiveAndBelow (tempAtomIndex, section->atoms.size()))
                break;

            auto& nextAtom = section->atoms.getReference (tempAtomIndex);
            nextLineWidth += nextAtom.width;

            if (shouldWrap (nextLineWidth) || nextAtom.isNewLine())
                break;

            if (checkSize)
            {
                lineHeight = jmax (lineHeight, section->font.getHeight());
                maxDescent = jmax (maxDescent, section->font.getDescent());
            }

            ++tempAtomIndex;
        }

        justificationOffset = getJustificationOffset (lineWidth);
        atomX = justificationOffset;
    }

    float getJustificationOffset (float lineWidth) const
    {
        if (justification.getOnlyHorizontalFlags() == Justification::horizontallyCentred)
            return jmax (0.0f, (justificationWidth - lineWidth) * 0.5f);

        if (justification.getOnlyHorizontalFlags() == Justification::right)
            return jmax (0.0f, justificationWidth - lineWidth);

        return 0;
    }

    //==============================================================================
    void draw (Graphics& g, const UniformTextSection*& lastSection) const
    {
        if (passwordCharacter != 0 || ! atom->isWhitespace())
        {
            if (lastSection != currentSection)
            {
                lastSection = currentSection;
                g.setColour (currentSection->colour);
                g.setFont (currentSection->font);
            }

            jassert (atom->getTrimmedText (passwordCharacter).isNotEmpty());

            GlyphArrangement ga;
            ga.addLineOfText (currentSection->font,
                              atom->getTrimmedText (passwordCharacter),
                              atomX, (float) roundToInt (lineY + lineHeight - maxDescent));
            ga.draw (g);
        }
    }

    void addSelection (RectangleList<float>& area, Range<int> selected) const
    {
        auto startX = indexToX (selected.getStart());
        auto endX   = indexToX (selected.getEnd());

        area.add (startX, lineY, endX - startX, lineHeight * lineSpacing);
    }

    void drawUnderline (Graphics& g, Range<int> underline, Colour colour) const
    {
        auto startX    = roundToInt (indexToX (underline.getStart()));
        auto endX      = roundToInt (indexToX (underline.getEnd()));
        auto baselineY = roundToInt (lineY + currentSection->font.getAscent() + 0.5f);

        Graphics::ScopedSaveState state (g);
        g.reduceClipRegion ({ startX, baselineY, endX - startX, 1 });
        g.fillCheckerBoard ({ (float) endX, baselineY + 1.0f }, 3.0f, 1.0f, colour, Colours::transparentBlack);
    }

    void drawSelectedText (Graphics& g, Range<int> selected, Colour selectedTextColour) const
    {
        if (passwordCharacter != 0 || ! atom->isWhitespace())
        {
            GlyphArrangement ga;
            ga.addLineOfText (currentSection->font,
                              atom->getTrimmedText (passwordCharacter),
                              atomX, (float) roundToInt (lineY + lineHeight - maxDescent));

            if (selected.getEnd() < indexInText + atom->numChars)
            {
                GlyphArrangement ga2 (ga);
                ga2.removeRangeOfGlyphs (0, selected.getEnd() - indexInText);
                ga.removeRangeOfGlyphs (selected.getEnd() - indexInText, -1);

                g.setColour (currentSection->colour);
                ga2.draw (g);
            }

            if (selected.getStart() > indexInText)
            {
                GlyphArrangement ga2 (ga);
                ga2.removeRangeOfGlyphs (selected.getStart() - indexInText, -1);
                ga.removeRangeOfGlyphs (0, selected.getStart() - indexInText);

                g.setColour (currentSection->colour);
                ga2.draw (g);
            }

            g.setColour (selectedTextColour);
            ga.draw (g);
        }
    }

    //==============================================================================
    float indexToX (int indexToFind) const
    {
        if (indexToFind <= indexInText)
            return atomX;

        if (indexToFind >= indexInText + atom->numChars)
            return atomRight;

        GlyphArrangement g;
        g.addLineOfText (currentSection->font,
                         atom->getText (passwordCharacter),
                         atomX, 0.0f);

        if (indexToFind - indexInText >= g.getNumGlyphs())
            return atomRight;

        return jmin (atomRight, g.getGlyph (indexToFind - indexInText).getLeft());
    }

    int xToIndex (float xToFind) const
    {
        if (xToFind <= atomX || atom->isNewLine())
            return indexInText;

        if (xToFind >= atomRight)
            return indexInText + atom->numChars;

        GlyphArrangement g;
        g.addLineOfText (currentSection->font,
                         atom->getText (passwordCharacter),
                         atomX, 0.0f);

        auto numGlyphs = g.getNumGlyphs();

        int j;
        for (j = 0; j < numGlyphs; ++j)
        {
            auto& pg = g.getGlyph(j);

            if ((pg.getLeft() + pg.getRight()) / 2 > xToFind)
                break;
        }

        return indexInText + j;
    }

    //==============================================================================
    bool getCharPosition (int index, Point<float>& anchor, float& lineHeightFound)
    {
        while (next())
        {
            if (indexInText + atom->numChars > index)
            {
                anchor = { indexToX (index), lineY };
                lineHeightFound = lineHeight;
                return true;
            }
        }

        anchor = { atomX, lineY };
        lineHeightFound = lineHeight;
        return false;
    }

    //==============================================================================
    int indexInText = 0;
    float lineY = 0, justificationOffset = 0, lineHeight = 0, maxDescent = 0;
    float atomX = 0, atomRight = 0;
    const TextAtom* atom = nullptr;
    const UniformTextSection* currentSection = nullptr;

private:
    const OwnedArray<UniformTextSection>& sections;
    int sectionIndex = 0, atomIndex = 0;
    Justification justification;
    const float justificationWidth, wordWrapWidth;
    const juce_wchar passwordCharacter;
    const float lineSpacing;
    TextAtom tempAtom;

    void moveToEndOfLastAtom()
    {
        if (atom != nullptr)
        {
            atomX = atomRight;

            if (atom->isNewLine())
            {
                atomX = 0.0f;
                lineY += lineHeight * lineSpacing;
            }
        }
    }

    bool shouldWrap (const float x) const noexcept
    {
        return (x - 0.0001f) >= wordWrapWidth;
    }

    JUCE_LEAK_DETECTOR (Iterator)
};


//==============================================================================
struct TextEditor::InsertAction  : public UndoableAction
{
    InsertAction (TextEditor& ed, const String& newText, int insertPos,
                  const Font& newFont, Colour newColour, int oldCaret, int newCaret)
        : owner (ed),
          text (newText),
          insertIndex (insertPos),
          oldCaretPos (oldCaret),
          newCaretPos (newCaret),
          font (newFont),
          colour (newColour)
    {
    }

    bool perform() override
    {
        owner.insert (text, insertIndex, font, colour, nullptr, newCaretPos);
        return true;
    }

    bool undo() override
    {
        owner.remove ({ insertIndex, insertIndex + text.length() }, nullptr, oldCaretPos);
        return true;
    }

    int getSizeInUnits() override
    {
        return text.length() + 16;
    }

private:
    TextEditor& owner;
    const String text;
    const int insertIndex, oldCaretPos, newCaretPos;
    const Font font;
    const Colour colour;

    JUCE_DECLARE_NON_COPYABLE (InsertAction)
};

//==============================================================================
struct TextEditor::RemoveAction  : public UndoableAction
{
    RemoveAction (TextEditor& ed, Range<int> rangeToRemove, int oldCaret, int newCaret,
                  const Array<UniformTextSection*>& oldSections)
        : owner (ed),
          range (rangeToRemove),
          oldCaretPos (oldCaret),
          newCaretPos (newCaret)
    {
        removedSections.addArray (oldSections);
    }

    bool perform() override
    {
        owner.remove (range, nullptr, newCaretPos);
        return true;
    }

    bool undo() override
    {
        owner.reinsert (range.getStart(), removedSections);
        owner.moveCaretTo (oldCaretPos, false);
        return true;
    }

    int getSizeInUnits() override
    {
        int n = 16;

        for (auto* s : removedSections)
            n += s->getTotalLength();

        return n;
    }

private:
    TextEditor& owner;
    const Range<int> range;
    const int oldCaretPos, newCaretPos;
    OwnedArray<UniformTextSection> removedSections;

    JUCE_DECLARE_NON_COPYABLE (RemoveAction)
};

//==============================================================================
struct TextEditor::TextHolderComponent  : public Component,
                                          public Timer,
                                          public Value::Listener
{
    TextHolderComponent (TextEditor& ed)  : owner (ed)
    {
        setWantsKeyboardFocus (false);
        setInterceptsMouseClicks (false, true);
        setMouseCursor (MouseCursor::ParentCursor);

        owner.getTextValue().addListener (this);
    }

    ~TextHolderComponent() override
    {
        owner.getTextValue().removeListener (this);
    }

    void paint (Graphics& g) override
    {
        owner.drawContent (g);
    }

    void restartTimer()
    {
        startTimer (350);
    }

    void timerCallback() override
    {
        owner.timerCallbackInt();
    }

    void valueChanged (Value&) override
    {
        owner.textWasChangedByValue();
    }

    TextEditor& owner;

    JUCE_DECLARE_NON_COPYABLE (TextHolderComponent)
};

//==============================================================================
struct TextEditor::TextEditorViewport  : public Viewport
{
    TextEditorViewport (TextEditor& ed) : owner (ed) {}

    void visibleAreaChanged (const Rectangle<int>&) override
    {
        if (! rentrant) // it's rare, but possible to get into a feedback loop as the viewport's scrollbars
                        // appear and disappear, causing the wrap width to change.
        {
            auto wordWrapWidth = owner.getWordWrapWidth();

            if (wordWrapWidth != lastWordWrapWidth)
            {
                lastWordWrapWidth = wordWrapWidth;

                rentrant = true;
                owner.updateTextHolderSize();
                rentrant = false;
            }
        }
    }

private:
    TextEditor& owner;
    float lastWordWrapWidth = 0;
    bool rentrant = false;

    JUCE_DECLARE_NON_COPYABLE (TextEditorViewport)
};

//==============================================================================
namespace TextEditorDefs
{
    const int textChangeMessageId = 0x10003001;
    const int returnKeyMessageId  = 0x10003002;
    const int escapeKeyMessageId  = 0x10003003;
    const int focusLossMessageId  = 0x10003004;

    const int maxActionsPerTransaction = 100;

    static int getCharacterCategory (juce_wchar character) noexcept
    {
        return CharacterFunctions::isLetterOrDigit (character)
                    ? 2 : (CharacterFunctions::isWhitespace (character) ? 0 : 1);
    }
}

//==============================================================================
TextEditor::TextEditor (const String& name, juce_wchar passwordChar)
    : Component (name),
      passwordCharacter (passwordChar)
{
    setMouseCursor (MouseCursor::IBeamCursor);

    viewport.reset (new TextEditorViewport (*this));
    addAndMakeVisible (viewport.get());
    viewport->setViewedComponent (textHolder = new TextHolderComponent (*this));
    viewport->setWantsKeyboardFocus (false);
    viewport->setScrollBarsShown (false, false);

    setWantsKeyboardFocus (true);
    recreateCaret();
}

TextEditor::~TextEditor()
{
    if (wasFocused)
        if (auto* peer = getPeer())
            peer->dismissPendingTextInput();

    textValue.removeListener (textHolder);
    textValue.referTo (Value());

    viewport.reset();
    textHolder = nullptr;
}

//==============================================================================
void TextEditor::newTransaction()
{
    lastTransactionTime = Time::getApproximateMillisecondCounter();
    undoManager.beginNewTransaction();
}

bool TextEditor::undoOrRedo (const bool shouldUndo)
{
    if (! isReadOnly())
    {
        newTransaction();

        if (shouldUndo ? undoManager.undo()
                       : undoManager.redo())
        {
            scrollToMakeSureCursorIsVisible();
            repaint();
            textChanged();
            return true;
        }
    }

    return false;
}

bool TextEditor::undo()     { return undoOrRedo (true); }
bool TextEditor::redo()     { return undoOrRedo (false); }

//==============================================================================
void TextEditor::setMultiLine (const bool shouldBeMultiLine,
                               const bool shouldWordWrap)
{
    if (multiline != shouldBeMultiLine
         || wordWrap != (shouldWordWrap && shouldBeMultiLine))
    {
        multiline = shouldBeMultiLine;
        wordWrap = shouldWordWrap && shouldBeMultiLine;

        viewport->setScrollBarsShown (scrollbarVisible && multiline,
                                      scrollbarVisible && multiline);
        viewport->setViewPosition (0, 0);
        resized();
        scrollToMakeSureCursorIsVisible();
    }
}

bool TextEditor::isMultiLine() const
{
    return multiline;
}

void TextEditor::setScrollbarsShown (bool shown)
{
    if (scrollbarVisible != shown)
    {
        scrollbarVisible = shown;
        shown = shown && isMultiLine();
        viewport->setScrollBarsShown (shown, shown);
    }
}

void TextEditor::setReadOnly (bool shouldBeReadOnly)
{
    if (readOnly != shouldBeReadOnly)
    {
        readOnly = shouldBeReadOnly;
        enablementChanged();
    }
}

bool TextEditor::isReadOnly() const noexcept
{
    return readOnly || ! isEnabled();
}

bool TextEditor::isTextInputActive() const
{
    return ! isReadOnly();
}

void TextEditor::setReturnKeyStartsNewLine (bool shouldStartNewLine)
{
    returnKeyStartsNewLine = shouldStartNewLine;
}

void TextEditor::setTabKeyUsedAsCharacter (bool shouldTabKeyBeUsed)
{
    tabKeyUsed = shouldTabKeyBeUsed;
}

void TextEditor::setPopupMenuEnabled (bool b)
{
    popupMenuEnabled = b;
}

void TextEditor::setSelectAllWhenFocused (bool b)
{
    selectAllTextWhenFocused = b;
}

void TextEditor::setJustification (Justification j)
{
    if (justification != j)
    {
        justification = j;
        resized();
    }
}

//==============================================================================
void TextEditor::setFont (const Font& newFont)
{
    currentFont = newFont;
    scrollToMakeSureCursorIsVisible();
}

void TextEditor::applyFontToAllText (const Font& newFont, bool changeCurrentFont)
{
    if (changeCurrentFont)
        currentFont = newFont;

    auto overallColour = findColour (textColourId);

    for (auto* uts : sections)
    {
        uts->setFont (newFont, passwordCharacter);
        uts->colour = overallColour;
    }

    coalesceSimilarSections();
    updateTextHolderSize();
    scrollToMakeSureCursorIsVisible();
    repaint();
}

void TextEditor::applyColourToAllText (const Colour& newColour, bool changeCurrentTextColour)
{
    for (auto* uts : sections)
        uts->colour = newColour;

    if (changeCurrentTextColour)
        setColour (TextEditor::textColourId, newColour);
    else
        repaint();
}

void TextEditor::lookAndFeelChanged()
{
    caret.reset();
    recreateCaret();
    repaint();
}

void TextEditor::parentHierarchyChanged()
{
    lookAndFeelChanged();
}

void TextEditor::enablementChanged()
{
    recreateCaret();
    repaint();
}

void TextEditor::setCaretVisible (bool shouldCaretBeVisible)
{
    if (caretVisible != shouldCaretBeVisible)
    {
        caretVisible = shouldCaretBeVisible;
        recreateCaret();
    }
}

void TextEditor::recreateCaret()
{
    if (isCaretVisible())
    {
        if (caret == nullptr)
        {
            caret.reset (getLookAndFeel().createCaretComponent (this));
            textHolder->addChildComponent (caret.get());
            updateCaretPosition();
        }
    }
    else
    {
        caret.reset();
    }
}

void TextEditor::updateCaretPosition()
{
    if (caret != nullptr)
        caret->setCaretPosition (getCaretRectangle().translated (leftIndent, topIndent));
}

TextEditor::LengthAndCharacterRestriction::LengthAndCharacterRestriction (int maxLen, const String& chars)
    : allowedCharacters (chars), maxLength (maxLen)
{
}

String TextEditor::LengthAndCharacterRestriction::filterNewText (TextEditor& ed, const String& newInput)
{
    String t (newInput);

    if (allowedCharacters.isNotEmpty())
        t = t.retainCharacters (allowedCharacters);

    if (maxLength > 0)
        t = t.substring (0, maxLength - (ed.getTotalNumChars() - ed.getHighlightedRegion().getLength()));

    return t;
}

void TextEditor::setInputFilter (InputFilter* newFilter, bool takeOwnership)
{
    inputFilter.set (newFilter, takeOwnership);
}

void TextEditor::setInputRestrictions (int maxLen, const String& chars)
{
    setInputFilter (new LengthAndCharacterRestriction (maxLen, chars), true);
}

void TextEditor::setTextToShowWhenEmpty (const String& text, Colour colourToUse)
{
    textToShowWhenEmpty = text;
    colourForTextWhenEmpty = colourToUse;
}

void TextEditor::setPasswordCharacter (juce_wchar newPasswordCharacter)
{
    if (passwordCharacter != newPasswordCharacter)
    {
        passwordCharacter = newPasswordCharacter;
        applyFontToAllText (currentFont);
    }
}

void TextEditor::setScrollBarThickness (int newThicknessPixels)
{
    viewport->setScrollBarThickness (newThicknessPixels);
}

//==============================================================================
void TextEditor::clear()
{
    clearInternal (nullptr);
    updateTextHolderSize();
    undoManager.clearUndoHistory();
}

void TextEditor::setText (const String& newText, bool sendTextChangeMessage)
{
    auto newLength = newText.length();

    if (newLength != getTotalNumChars() || getText() != newText)
    {
        if (! sendTextChangeMessage)
            textValue.removeListener (textHolder);

        textValue = newText;

        auto oldCursorPos = caretPosition;
        bool cursorWasAtEnd = oldCursorPos >= getTotalNumChars();

        clearInternal (nullptr);
        insert (newText, 0, currentFont, findColour (textColourId), nullptr, caretPosition);

        // if you're adding text with line-feeds to a single-line text editor, it
        // ain't gonna look right!
        jassert (multiline || ! newText.containsAnyOf ("\r\n"));

        if (cursorWasAtEnd && ! isMultiLine())
            oldCursorPos = getTotalNumChars();

        moveCaretTo (oldCursorPos, false);

        if (sendTextChangeMessage)
            textChanged();
        else
            textValue.addListener (textHolder);

        updateTextHolderSize();
        scrollToMakeSureCursorIsVisible();
        undoManager.clearUndoHistory();

        repaint();
    }
}

//==============================================================================
void TextEditor::updateValueFromText()
{
    if (valueTextNeedsUpdating)
    {
        valueTextNeedsUpdating = false;
        textValue = getText();
    }
}

Value& TextEditor::getTextValue()
{
    updateValueFromText();
    return textValue;
}

void TextEditor::textWasChangedByValue()
{
    if (textValue.getValueSource().getReferenceCount() > 1)
        setText (textValue.getValue());
}

//==============================================================================
void TextEditor::textChanged()
{
    updateTextHolderSize();

    if (listeners.size() != 0 || onTextChange != nullptr)
        postCommandMessage (TextEditorDefs::textChangeMessageId);

    if (textValue.getValueSource().getReferenceCount() > 1)
    {
        valueTextNeedsUpdating = false;
        textValue = getText();
    }
}

void TextEditor::returnPressed()    { postCommandMessage (TextEditorDefs::returnKeyMessageId); }
void TextEditor::escapePressed()    { postCommandMessage (TextEditorDefs::escapeKeyMessageId); }

void TextEditor::addListener (Listener* l)      { listeners.add (l); }
void TextEditor::removeListener (Listener* l)   { listeners.remove (l); }

//==============================================================================
void TextEditor::timerCallbackInt()
{
    checkFocus();

    auto now = Time::getApproximateMillisecondCounter();

    if (now > lastTransactionTime + 200)
        newTransaction();
}

void TextEditor::checkFocus()
{
    if (! wasFocused && hasKeyboardFocus (false) && ! isCurrentlyBlockedByAnotherModalComponent())
    {
        wasFocused = true;

        if (auto* peer = getPeer())
            if (! isReadOnly())
                peer->textInputRequired (peer->globalToLocal (getScreenPosition()), *this);
    }
}

void TextEditor::repaintText (Range<int> range)
{
    if (! range.isEmpty())
    {
        auto lh = currentFont.getHeight();
        auto wordWrapWidth = getWordWrapWidth();

        if (wordWrapWidth > 0)
        {
            Point<float> anchor;
            Iterator i (*this);
            i.getCharPosition (range.getStart(), anchor, lh);

            auto y1 = (int) anchor.y;
            int y2;

            if (range.getEnd() >= getTotalNumChars())
            {
                y2 = textHolder->getHeight();
            }
            else
            {
                i.getCharPosition (range.getEnd(), anchor, lh);
                y2 = (int) (anchor.y + lh * 2.0f);
            }

            textHolder->repaint (0, y1, textHolder->getWidth(), y2 - y1);
        }
    }
}

//==============================================================================
void TextEditor::moveCaret (int newCaretPos)
{
    if (newCaretPos < 0)
        newCaretPos = 0;
    else
        newCaretPos = jmin (newCaretPos, getTotalNumChars());

    if (newCaretPos != getCaretPosition())
    {
        caretPosition = newCaretPos;
        textHolder->restartTimer();
        scrollToMakeSureCursorIsVisible();
        updateCaretPosition();
    }
}

int TextEditor::getCaretPosition() const
{
    return caretPosition;
}

void TextEditor::setCaretPosition (const int newIndex)
{
    moveCaretTo (newIndex, false);
}

void TextEditor::moveCaretToEnd()
{
    setCaretPosition (std::numeric_limits<int>::max());
}

void TextEditor::scrollEditorToPositionCaret (const int desiredCaretX,
                                              const int desiredCaretY)

{
    updateCaretPosition();
    auto caretPos = getCaretRectangle();

    auto vx = caretPos.getX() - desiredCaretX;
    auto vy = caretPos.getY() - desiredCaretY;

    if (desiredCaretX < jmax (1, proportionOfWidth (0.05f)))
        vx += desiredCaretX - proportionOfWidth (0.2f);
    else if (desiredCaretX > jmax (0, viewport->getMaximumVisibleWidth() - (wordWrap ? 2 : 10)))
        vx += desiredCaretX + (isMultiLine() ? proportionOfWidth (0.2f) : 10) - viewport->getMaximumVisibleWidth();

    vx = jlimit (0, jmax (0, textHolder->getWidth() + 8 - viewport->getMaximumVisibleWidth()), vx);

    if (! isMultiLine())
    {
        vy = viewport->getViewPositionY();
    }
    else
    {
        vy = jlimit (0, jmax (0, textHolder->getHeight() - viewport->getMaximumVisibleHeight()), vy);

        if (desiredCaretY < 0)
            vy = jmax (0, desiredCaretY + vy);
        else if (desiredCaretY > jmax (0, viewport->getMaximumVisibleHeight() - topIndent - caretPos.getHeight()))
            vy += desiredCaretY + 2 + caretPos.getHeight() + topIndent - viewport->getMaximumVisibleHeight();
    }

    viewport->setViewPosition (vx, vy);
}

Rectangle<int> TextEditor::getCaretRectangle()
{
    return getCaretRectangleFloat().getSmallestIntegerContainer();
}

Rectangle<float> TextEditor::getCaretRectangleFloat() const
{
    Point<float> anchor;
    auto cursorHeight = currentFont.getHeight(); // (in case the text is empty and the call below doesn't set this value)
    getCharPosition (caretPosition, anchor, cursorHeight);

    return { anchor.x, anchor.y, 2.0f, cursorHeight };
}

//==============================================================================
enum { rightEdgeSpace = 2 };

float TextEditor::getWordWrapWidth() const
{
    return wordWrap ? getJustificationWidth()
                    : std::numeric_limits<float>::max();
}

float TextEditor::getJustificationWidth() const
{
    return (float) (viewport->getMaximumVisibleWidth() - (leftIndent + rightEdgeSpace + 1));
}

void TextEditor::updateTextHolderSize()
{
    if (getWordWrapWidth() > 0)
    {
        float maxWidth = getJustificationWidth();
        Iterator i (*this);

        while (i.next())
            maxWidth = jmax (maxWidth, i.atomRight);

        auto w = leftIndent + roundToInt (maxWidth);
        auto h = topIndent + roundToInt (jmax (i.lineY + i.lineHeight, currentFont.getHeight()));

        textHolder->setSize (w + rightEdgeSpace, h + 1); // (allows a bit of space for the cursor to be at the right-hand-edge)
    }
}

int TextEditor::getTextWidth() const    { return textHolder->getWidth(); }
int TextEditor::getTextHeight() const   { return textHolder->getHeight(); }

void TextEditor::setIndents (int newLeftIndent, int newTopIndent)
{
    leftIndent = newLeftIndent;
    topIndent  = newTopIndent;
}

void TextEditor::setBorder (BorderSize<int> border)
{
    borderSize = border;
    resized();
}

BorderSize<int> TextEditor::getBorder() const
{
    return borderSize;
}

void TextEditor::setScrollToShowCursor (const bool shouldScrollToShowCursor)
{
    keepCaretOnScreen = shouldScrollToShowCursor;
}

void TextEditor::scrollToMakeSureCursorIsVisible()
{
    updateCaretPosition();

    if (keepCaretOnScreen)
    {
        auto viewPos = viewport->getViewPosition();
        auto caretRect = getCaretRectangle();
        auto relativeCursor = caretRect.getPosition() - viewPos;

        if (relativeCursor.x < jmax (1, proportionOfWidth (0.05f)))
        {
            viewPos.x += relativeCursor.x - proportionOfWidth (0.2f);
        }
        else if (relativeCursor.x > jmax (0, viewport->getMaximumVisibleWidth() - (wordWrap ? 2 : 10)))
        {
            viewPos.x += relativeCursor.x + (isMultiLine() ? proportionOfWidth (0.2f) : 10) - viewport->getMaximumVisibleWidth();
        }

        viewPos.x = jlimit (0, jmax (0, textHolder->getWidth() + 8 - viewport->getMaximumVisibleWidth()), viewPos.x);

        if (! isMultiLine())
        {
            viewPos.y = (getHeight() - textHolder->getHeight() - topIndent) / -2;
        }
        else if (relativeCursor.y < 0)
        {
            viewPos.y = jmax (0, relativeCursor.y + viewPos.y);
        }
        else if (relativeCursor.y > jmax (0, viewport->getMaximumVisibleHeight() - topIndent - caretRect.getHeight()))
        {
            viewPos.y += relativeCursor.y + 2 + caretRect.getHeight() + topIndent - viewport->getMaximumVisibleHeight();
        }

        viewport->setViewPosition (viewPos);
    }
}

void TextEditor::moveCaretTo (const int newPosition, const bool isSelecting)
{
    if (isSelecting)
    {
        moveCaret (newPosition);

        auto oldSelection = selection;

        if (dragType == notDragging)
        {
            if (std::abs (getCaretPosition() - selection.getStart()) < std::abs (getCaretPosition() - selection.getEnd()))
                dragType = draggingSelectionStart;
            else
                dragType = draggingSelectionEnd;
        }

        if (dragType == draggingSelectionStart)
        {
            if (getCaretPosition() >= selection.getEnd())
                dragType = draggingSelectionEnd;

            selection = Range<int>::between (getCaretPosition(), selection.getEnd());
        }
        else
        {
            if (getCaretPosition() < selection.getStart())
                dragType = draggingSelectionStart;

            selection = Range<int>::between (getCaretPosition(), selection.getStart());
        }

        repaintText (selection.getUnionWith (oldSelection));
    }
    else
    {
        dragType = notDragging;

        repaintText (selection);

        moveCaret (newPosition);
        selection = Range<int>::emptyRange (getCaretPosition());
    }
}

int TextEditor::getTextIndexAt (const int x, const int y)
{
    return indexAtPosition ((float) (x + viewport->getViewPositionX() - leftIndent - borderSize.getLeft()),
                            (float) (y + viewport->getViewPositionY() - topIndent  - borderSize.getTop()));
}

void TextEditor::insertTextAtCaret (const String& t)
{
    String newText (inputFilter != nullptr ? inputFilter->filterNewText (*this, t) : t);

    if (isMultiLine())
        newText = newText.replace ("\r\n", "\n");
    else
        newText = newText.replaceCharacters ("\r\n", "  ");

    const int insertIndex = selection.getStart();
    const int newCaretPos = insertIndex + newText.length();

    remove (selection, getUndoManager(),
            newText.isNotEmpty() ? newCaretPos - 1 : newCaretPos);

    insert (newText, insertIndex, currentFont, findColour (textColourId),
            getUndoManager(), newCaretPos);

    textChanged();
}

void TextEditor::setHighlightedRegion (const Range<int>& newSelection)
{
    moveCaretTo (newSelection.getStart(), false);
    moveCaretTo (newSelection.getEnd(), true);
}

//==============================================================================
void TextEditor::copy()
{
    if (passwordCharacter == 0)
    {
        auto selectedText = getHighlightedText();

        if (selectedText.isNotEmpty())
            SystemClipboard::copyTextToClipboard (selectedText);
    }
}

void TextEditor::paste()
{
    if (! isReadOnly())
    {
        auto clip = SystemClipboard::getTextFromClipboard();

        if (clip.isNotEmpty())
            insertTextAtCaret (clip);
    }
}

void TextEditor::cut()
{
    if (! isReadOnly())
    {
        moveCaret (selection.getEnd());
        insertTextAtCaret (String());
    }
}

//==============================================================================
void TextEditor::drawContent (Graphics& g)
{
    if (getWordWrapWidth() > 0)
    {
        g.setOrigin (leftIndent, topIndent);
        auto clip = g.getClipBounds();
        Colour selectedTextColour;
        Iterator i (*this);

        if (! selection.isEmpty())
        {
            Iterator i2 (i);
            RectangleList<float> selectionArea;

            while (i2.next() && i2.lineY < clip.getBottom())
            {
                if (i2.lineY + i2.lineHeight >= clip.getY()
                    && selection.intersects ({ i2.indexInText, i2.indexInText + i2.atom->numChars }))
                {
                    i2.addSelection (selectionArea, selection);
                }
            }

            g.setColour (findColour (highlightColourId).withMultipliedAlpha (hasKeyboardFocus (true) ? 1.0f : 0.5f));
            g.fillRectList (selectionArea);

            selectedTextColour = findColour (highlightedTextColourId);
        }

        const UniformTextSection* lastSection = nullptr;

        while (i.next() && i.lineY < clip.getBottom())
        {
            if (i.lineY + i.lineHeight >= clip.getY())
            {
                if (selection.intersects ({ i.indexInText, i.indexInText + i.atom->numChars }))
                {
                    i.drawSelectedText (g, selection, selectedTextColour);
                    lastSection = nullptr;
                }
                else
                {
                    i.draw (g, lastSection);
                }
            }
        }

        for (auto& underlinedSection : underlinedSections)
        {
            Iterator i2 (*this);

            while (i2.next() && i2.lineY < clip.getBottom())
            {
                if (i2.lineY + i2.lineHeight >= clip.getY()
                      && underlinedSection.intersects ({ i2.indexInText, i2.indexInText + i2.atom->numChars }))
                {
                    i2.drawUnderline (g, underlinedSection, findColour (textColourId));
                }
            }
        }
    }
}

void TextEditor::paint (Graphics& g)
{
    getLookAndFeel().fillTextEditorBackground (g, getWidth(), getHeight(), *this);
}

void TextEditor::paintOverChildren (Graphics& g)
{
    if (textToShowWhenEmpty.isNotEmpty()
         && (! hasKeyboardFocus (false))
         && getTotalNumChars() == 0)
    {
        g.setColour (colourForTextWhenEmpty);
        g.setFont (getFont());

        if (isMultiLine())
            g.drawText (textToShowWhenEmpty, getLocalBounds(),
                        Justification::centred, true);
        else
            g.drawText (textToShowWhenEmpty,
                        leftIndent, 0, viewport->getWidth() - leftIndent, getHeight(),
                        Justification::centredLeft, true);
    }

    getLookAndFeel().drawTextEditorOutline (g, getWidth(), getHeight(), *this);
}

//==============================================================================
void TextEditor::addPopupMenuItems (PopupMenu& m, const MouseEvent*)
{
    const bool writable = ! isReadOnly();

    if (passwordCharacter == 0)
    {
        m.addItem (StandardApplicationCommandIDs::cut,   TRANS("Cut"), writable);
        m.addItem (StandardApplicationCommandIDs::copy,  TRANS("Copy"), ! selection.isEmpty());
    }

    m.addItem (StandardApplicationCommandIDs::paste,     TRANS("Paste"), writable);
    m.addItem (StandardApplicationCommandIDs::del,       TRANS("Delete"), writable);
    m.addSeparator();
    m.addItem (StandardApplicationCommandIDs::selectAll, TRANS("Select All"));
    m.addSeparator();

    if (getUndoManager() != nullptr)
    {
        m.addItem (StandardApplicationCommandIDs::undo, TRANS("Undo"), undoManager.canUndo());
        m.addItem (StandardApplicationCommandIDs::redo, TRANS("Redo"), undoManager.canRedo());
    }
}

void TextEditor::performPopupMenuAction (const int menuItemID)
{
    switch (menuItemID)
    {
        case StandardApplicationCommandIDs::cut:        cutToClipboard(); break;
        case StandardApplicationCommandIDs::copy:       copyToClipboard(); break;
        case StandardApplicationCommandIDs::paste:      pasteFromClipboard(); break;
        case StandardApplicationCommandIDs::del:        cut(); break;
        case StandardApplicationCommandIDs::selectAll:  selectAll(); break;
        case StandardApplicationCommandIDs::undo:       undo(); break;
        case StandardApplicationCommandIDs::redo:       redo(); break;
        default: break;
    }
}

//==============================================================================
void TextEditor::mouseDown (const MouseEvent& e)
{
    beginDragAutoRepeat (100);
    newTransaction();

    if (wasFocused || ! selectAllTextWhenFocused)
    {
        if (! (popupMenuEnabled && e.mods.isPopupMenu()))
        {
            moveCaretTo (getTextIndexAt (e.x, e.y),
                         e.mods.isShiftDown());
        }
        else
        {
            PopupMenu m;
            m.setLookAndFeel (&getLookAndFeel());
            addPopupMenuItems (m, &e);

            menuActive = true;

            SafePointer<TextEditor> safeThis (this);

            m.showMenuAsync (PopupMenu::Options(),
                             [safeThis] (int menuResult)
                             {
                                 if (auto* editor = safeThis.getComponent())
                                 {
                                     editor->menuActive = false;

                                     if (menuResult != 0)
                                         editor->performPopupMenuAction (menuResult);
                                 }
                             });
        }
    }
}

void TextEditor::mouseDrag (const MouseEvent& e)
{
    if (wasFocused || ! selectAllTextWhenFocused)
        if (! (popupMenuEnabled && e.mods.isPopupMenu()))
            moveCaretTo (getTextIndexAt (e.x, e.y), true);
}

void TextEditor::mouseUp (const MouseEvent& e)
{
    newTransaction();
    textHolder->restartTimer();

    if (wasFocused || ! selectAllTextWhenFocused)
        if (e.mouseWasClicked() && ! (popupMenuEnabled && e.mods.isPopupMenu()))
            moveCaret (getTextIndexAt (e.x, e.y));

    wasFocused = true;
}

void TextEditor::mouseDoubleClick (const MouseEvent& e)
{
    int tokenEnd = getTextIndexAt (e.x, e.y);
    int tokenStart = 0;

    if (e.getNumberOfClicks() > 3)
    {
        tokenEnd = getTotalNumChars();
    }
    else
    {
        auto t = getText();
        auto totalLength = getTotalNumChars();

        while (tokenEnd < totalLength)
        {
            auto c = t[tokenEnd];

            // (note the slight bodge here - it's because iswalnum only checks for alphabetic chars in the current locale)
            if (CharacterFunctions::isLetterOrDigit (c) || c > 128)
                ++tokenEnd;
            else
                break;
        }

        tokenStart = tokenEnd;

        while (tokenStart > 0)
        {
            auto c = t[tokenStart - 1];

            // (note the slight bodge here - it's because iswalnum only checks for alphabetic chars in the current locale)
            if (CharacterFunctions::isLetterOrDigit (c) || c > 128)
                --tokenStart;
            else
                break;
        }

        if (e.getNumberOfClicks() > 2)
        {
            while (tokenEnd < totalLength)
            {
                auto c = t[tokenEnd];

                if (c != '\r' && c != '\n')
                    ++tokenEnd;
                else
                    break;
            }

            while (tokenStart > 0)
            {
                auto c = t[tokenStart - 1];

                if (c != '\r' && c != '\n')
                    --tokenStart;
                else
                    break;
            }
        }
    }

    moveCaretTo (tokenEnd, false);
    moveCaretTo (tokenStart, true);
}

void TextEditor::mouseWheelMove (const MouseEvent& e, const MouseWheelDetails& wheel)
{
    if (! viewport->useMouseWheelMoveIfNeeded (e, wheel))
        Component::mouseWheelMove (e, wheel);
}

//==============================================================================
bool TextEditor::moveCaretWithTransaction (const int newPos, const bool selecting)
{
    newTransaction();
    moveCaretTo (newPos, selecting);
    return true;
}

bool TextEditor::moveCaretLeft (bool moveInWholeWordSteps, bool selecting)
{
    auto pos = getCaretPosition();

    if (moveInWholeWordSteps)
        pos = findWordBreakBefore (pos);
    else
        --pos;

    return moveCaretWithTransaction (pos, selecting);
}

bool TextEditor::moveCaretRight (bool moveInWholeWordSteps, bool selecting)
{
    auto pos = getCaretPosition();

    if (moveInWholeWordSteps)
        pos = findWordBreakAfter (pos);
    else
        ++pos;

    return moveCaretWithTransaction (pos, selecting);
}

bool TextEditor::moveCaretUp (bool selecting)
{
    if (! isMultiLine())
        return moveCaretToStartOfLine (selecting);

    auto caretPos = getCaretRectangleFloat();
    return moveCaretWithTransaction (indexAtPosition (caretPos.getX(), caretPos.getY() - 1.0f), selecting);
}

bool TextEditor::moveCaretDown (bool selecting)
{
    if (! isMultiLine())
        return moveCaretToEndOfLine (selecting);

    auto caretPos = getCaretRectangleFloat();
    return moveCaretWithTransaction (indexAtPosition (caretPos.getX(), caretPos.getBottom() + 1.0f), selecting);
}

bool TextEditor::pageUp (bool selecting)
{
    if (! isMultiLine())
        return moveCaretToStartOfLine (selecting);

    auto caretPos = getCaretRectangleFloat();
    return moveCaretWithTransaction (indexAtPosition (caretPos.getX(), caretPos.getY() - viewport->getViewHeight()), selecting);
}

bool TextEditor::pageDown (bool selecting)
{
    if (! isMultiLine())
        return moveCaretToEndOfLine (selecting);

    auto caretPos = getCaretRectangleFloat();
    return moveCaretWithTransaction (indexAtPosition (caretPos.getX(), caretPos.getBottom() + viewport->getViewHeight()), selecting);
}

void TextEditor::scrollByLines (int deltaLines)
{
    viewport->getVerticalScrollBar().moveScrollbarInSteps (deltaLines);
}

bool TextEditor::scrollDown()
{
    scrollByLines (-1);
    return true;
}

bool TextEditor::scrollUp()
{
    scrollByLines (1);
    return true;
}

bool TextEditor::moveCaretToTop (bool selecting)
{
    return moveCaretWithTransaction (0, selecting);
}

bool TextEditor::moveCaretToStartOfLine (bool selecting)
{
    auto caretPos = getCaretRectangleFloat();
    return moveCaretWithTransaction (indexAtPosition (0.0f, caretPos.getY()), selecting);
}

bool TextEditor::moveCaretToEnd (bool selecting)
{
    return moveCaretWithTransaction (getTotalNumChars(), selecting);
}

bool TextEditor::moveCaretToEndOfLine (bool selecting)
{
    auto caretPos = getCaretRectangleFloat();
    return moveCaretWithTransaction (indexAtPosition ((float) textHolder->getWidth(), caretPos.getY()), selecting);
}

bool TextEditor::deleteBackwards (bool moveInWholeWordSteps)
{
    if (moveInWholeWordSteps)
        moveCaretTo (findWordBreakBefore (getCaretPosition()), true);
    else if (selection.isEmpty() && selection.getStart() > 0)
        selection = { selection.getEnd() - 1, selection.getEnd() };

    cut();
    return true;
}

bool TextEditor::deleteForwards (bool /*moveInWholeWordSteps*/)
{
    if (selection.isEmpty() && selection.getStart() < getTotalNumChars())
        selection = { selection.getStart(), selection.getStart() + 1 };

    cut();
    return true;
}

bool TextEditor::copyToClipboard()
{
    newTransaction();
    copy();
    return true;
}

bool TextEditor::cutToClipboard()
{
    newTransaction();
    copy();
    cut();
    return true;
}

bool TextEditor::pasteFromClipboard()
{
    newTransaction();
    paste();
    return true;
}

bool TextEditor::selectAll()
{
    newTransaction();
    moveCaretTo (getTotalNumChars(), false);
    moveCaretTo (0, true);
    return true;
}

//==============================================================================
void TextEditor::setEscapeAndReturnKeysConsumed (bool shouldBeConsumed) noexcept
{
    consumeEscAndReturnKeys = shouldBeConsumed;
}

bool TextEditor::keyPressed (const KeyPress& key)
{
    if (isReadOnly() && key != KeyPress ('c', ModifierKeys::commandModifier, 0)
                     && key != KeyPress ('a', ModifierKeys::commandModifier, 0))
        return false;

    if (! TextEditorKeyMapper<TextEditor>::invokeKeyFunction (*this, key))
    {
        if (key == KeyPress::returnKey)
        {
            newTransaction();

            if (returnKeyStartsNewLine)
            {
                insertTextAtCaret ("\n");
            }
            else
            {
                returnPressed();
                return consumeEscAndReturnKeys;
            }
        }
        else if (key.isKeyCode (KeyPress::escapeKey))
        {
            newTransaction();
            moveCaretTo (getCaretPosition(), false);
            escapePressed();
            return consumeEscAndReturnKeys;
        }
        else if (key.getTextCharacter() >= ' '
                  || (tabKeyUsed && (key.getTextCharacter() == '\t')))
        {
            insertTextAtCaret (String::charToString (key.getTextCharacter()));

            lastTransactionTime = Time::getApproximateMillisecondCounter();
        }
        else
        {
            return false;
        }
    }

    return true;
}

bool TextEditor::keyStateChanged (const bool isKeyDown)
{
    if (! isKeyDown)
        return false;

   #if JUCE_WINDOWS
    if (KeyPress (KeyPress::F4Key, ModifierKeys::altModifier, 0).isCurrentlyDown())
        return false;  // We need to explicitly allow alt-F4 to pass through on Windows
   #endif

    if ((! consumeEscAndReturnKeys)
         && (KeyPress (KeyPress::escapeKey).isCurrentlyDown()
          || KeyPress (KeyPress::returnKey).isCurrentlyDown()))
        return false;

    // (overridden to avoid forwarding key events to the parent)
    return ! ModifierKeys::currentModifiers.isCommandDown();
}

//==============================================================================
void TextEditor::focusGained (FocusChangeType)
{
    newTransaction();

    if (selectAllTextWhenFocused)
    {
        moveCaretTo (0, false);
        moveCaretTo (getTotalNumChars(), true);
    }

    checkFocus();

    repaint();
    updateCaretPosition();
}

void TextEditor::focusLost (FocusChangeType)
{
    newTransaction();

    wasFocused = false;
    textHolder->stopTimer();

    underlinedSections.clear();

    if (auto* peer = getPeer())
        peer->dismissPendingTextInput();

    updateCaretPosition();

    postCommandMessage (TextEditorDefs::focusLossMessageId);
    repaint();
}

//==============================================================================
void TextEditor::resized()
{
    viewport->setBoundsInset (borderSize);
    viewport->setSingleStepSizes (16, roundToInt (currentFont.getHeight()));

    updateTextHolderSize();

    if (isMultiLine())
        updateCaretPosition();
    else
        scrollToMakeSureCursorIsVisible();
}

void TextEditor::handleCommandMessage (const int commandId)
{
    Component::BailOutChecker checker (this);

    switch (commandId)
    {
    case TextEditorDefs::textChangeMessageId:
        listeners.callChecked (checker, [this] (Listener& l) { l.textEditorTextChanged (*this); });

        if (! checker.shouldBailOut() && onTextChange != nullptr)
            onTextChange();

        break;

    case TextEditorDefs::returnKeyMessageId:
        listeners.callChecked (checker, [this] (Listener& l) { l.textEditorReturnKeyPressed (*this); });

        if (! checker.shouldBailOut() && onReturnKey != nullptr)
            onReturnKey();

        break;

    case TextEditorDefs::escapeKeyMessageId:
        listeners.callChecked (checker, [this] (Listener& l) { l.textEditorEscapeKeyPressed (*this); });

        if (! checker.shouldBailOut() && onEscapeKey != nullptr)
            onEscapeKey();

        break;

    case TextEditorDefs::focusLossMessageId:
        updateValueFromText();
        listeners.callChecked (checker, [this] (Listener& l) { l.textEditorFocusLost (*this); });

        if (! checker.shouldBailOut() && onFocusLost != nullptr)
            onFocusLost();

        break;

    default:
        jassertfalse;
        break;
    }
}

void TextEditor::setTemporaryUnderlining (const Array<Range<int>>& newUnderlinedSections)
{
    underlinedSections = newUnderlinedSections;
    repaint();
}

//==============================================================================
UndoManager* TextEditor::getUndoManager() noexcept
{
    return readOnly ? nullptr : &undoManager;
}

void TextEditor::clearInternal (UndoManager* const um)
{
    remove ({ 0, getTotalNumChars() }, um, caretPosition);
}

void TextEditor::insert (const String& text, int insertIndex, const Font& font,
                         Colour colour, UndoManager* um, int caretPositionToMoveTo)
{
    if (text.isNotEmpty())
    {
        if (um != nullptr)
        {
            if (um->getNumActionsInCurrentTransaction() > TextEditorDefs::maxActionsPerTransaction)
                newTransaction();

            um->perform (new InsertAction (*this, text, insertIndex, font, colour,
                                           caretPosition, caretPositionToMoveTo));
        }
        else
        {
            repaintText ({ insertIndex, getTotalNumChars() }); // must do this before and after changing the data, in case
                                                               // a line gets moved due to word wrap

            int index = 0;
            int nextIndex = 0;

            for (int i = 0; i < sections.size(); ++i)
            {
                nextIndex = index + sections.getUnchecked (i)->getTotalLength();

                if (insertIndex == index)
                {
                    sections.insert (i, new UniformTextSection (text, font, colour, passwordCharacter));
                    break;
                }

                if (insertIndex > index && insertIndex < nextIndex)
                {
                    splitSection (i, insertIndex - index);
                    sections.insert (i + 1, new UniformTextSection (text, font, colour, passwordCharacter));
                    break;
                }

                index = nextIndex;
            }

            if (nextIndex == insertIndex)
                sections.add (new UniformTextSection (text, font, colour, passwordCharacter));

            coalesceSimilarSections();
            totalNumChars = -1;
            valueTextNeedsUpdating = true;

            updateTextHolderSize();
            moveCaretTo (caretPositionToMoveTo, false);

            repaintText ({ insertIndex, getTotalNumChars() });
        }
    }
}

void TextEditor::reinsert (int insertIndex, const OwnedArray<UniformTextSection>& sectionsToInsert)
{
    int index = 0;
    int nextIndex = 0;

    for (int i = 0; i < sections.size(); ++i)
    {
        nextIndex = index + sections.getUnchecked (i)->getTotalLength();

        if (insertIndex == index)
        {
            for (int j = sectionsToInsert.size(); --j >= 0;)
                sections.insert (i, new UniformTextSection (*sectionsToInsert.getUnchecked(j)));

            break;
        }

        if (insertIndex > index && insertIndex < nextIndex)
        {
            splitSection (i, insertIndex - index);

            for (int j = sectionsToInsert.size(); --j >= 0;)
                sections.insert (i + 1, new UniformTextSection (*sectionsToInsert.getUnchecked(j)));

            break;
        }

        index = nextIndex;
    }

    if (nextIndex == insertIndex)
        for (auto* s : sectionsToInsert)
            sections.add (new UniformTextSection (*s));

    coalesceSimilarSections();
    totalNumChars = -1;
    valueTextNeedsUpdating = true;
}

void TextEditor::remove (Range<int> range, UndoManager* const um, const int caretPositionToMoveTo)
{
    if (! range.isEmpty())
    {
        int index = 0;

        for (int i = 0; i < sections.size(); ++i)
        {
            auto nextIndex = index + sections.getUnchecked(i)->getTotalLength();

            if (range.getStart() > index && range.getStart() < nextIndex)
            {
                splitSection (i, range.getStart() - index);
                --i;
            }
            else if (range.getEnd() > index && range.getEnd() < nextIndex)
            {
                splitSection (i, range.getEnd() - index);
                --i;
            }
            else
            {
                index = nextIndex;

                if (index > range.getEnd())
                    break;
            }
        }

        index = 0;

        if (um != nullptr)
        {
            Array<UniformTextSection*> removedSections;

            for (auto* section : sections)
            {
                if (range.getEnd() <= range.getStart())
                    break;

                auto nextIndex = index + section->getTotalLength();

                if (range.getStart() <= index && range.getEnd() >= nextIndex)
                    removedSections.add (new UniformTextSection (*section));

                index = nextIndex;
            }

            if (um->getNumActionsInCurrentTransaction() > TextEditorDefs::maxActionsPerTransaction)
                newTransaction();

            um->perform (new RemoveAction (*this, range, caretPosition,
                                           caretPositionToMoveTo, removedSections));
        }
        else
        {
            auto remainingRange = range;

            for (int i = 0; i < sections.size(); ++i)
            {
                auto* section = sections.getUnchecked (i);
                auto nextIndex = index + section->getTotalLength();

                if (remainingRange.getStart() <= index && remainingRange.getEnd() >= nextIndex)
                {
                    sections.remove (i);
                    remainingRange.setEnd (remainingRange.getEnd() - (nextIndex - index));

                    if (remainingRange.isEmpty())
                        break;

                    --i;
                }
                else
                {
                    index = nextIndex;
                }
            }

            coalesceSimilarSections();
            totalNumChars = -1;
            valueTextNeedsUpdating = true;

            moveCaretTo (caretPositionToMoveTo, false);

            repaintText ({ range.getStart(), getTotalNumChars() });
        }
    }
}

//==============================================================================
String TextEditor::getText() const
{
    MemoryOutputStream mo;
    mo.preallocate ((size_t) getTotalNumChars());

    for (auto* s : sections)
        s->appendAllText (mo);

    return mo.toUTF8();
}

String TextEditor::getTextInRange (const Range<int>& range) const
{
    if (range.isEmpty())
        return {};

    MemoryOutputStream mo;
    mo.preallocate ((size_t) jmin (getTotalNumChars(), range.getLength()));

    int index = 0;

    for (auto* s : sections)
    {
        auto nextIndex = index + s->getTotalLength();

        if (range.getStart() < nextIndex)
        {
            if (range.getEnd() <= index)
                break;

            s->appendSubstring (mo, range - index);
        }

        index = nextIndex;
    }

    return mo.toUTF8();
}

String TextEditor::getHighlightedText() const
{
    return getTextInRange (selection);
}

int TextEditor::getTotalNumChars() const
{
    if (totalNumChars < 0)
    {
        totalNumChars = 0;

        for (auto* s : sections)
            totalNumChars += s->getTotalLength();
    }

    return totalNumChars;
}

bool TextEditor::isEmpty() const
{
    return getTotalNumChars() == 0;
}

void TextEditor::getCharPosition (int index, Point<float>& anchor, float& lineHeight) const
{
    if (getWordWrapWidth() <= 0)
    {
        anchor = {};
        lineHeight = currentFont.getHeight();
    }
    else
    {
        Iterator i (*this);

        if (sections.isEmpty())
        {
            anchor = { i.getJustificationOffset (0), 0 };
            lineHeight = currentFont.getHeight();
        }
        else
        {
            i.getCharPosition (index, anchor, lineHeight);
        }
    }
}

int TextEditor::indexAtPosition (const float x, const float y)
{
    if (getWordWrapWidth() > 0)
    {
        for (Iterator i (*this); i.next();)
        {
            if (y < i.lineY + i.lineHeight)
            {
                if (y < i.lineY)
                    return jmax (0, i.indexInText - 1);

                if (x <= i.atomX || i.atom->isNewLine())
                    return i.indexInText;

                if (x < i.atomRight)
                    return i.xToIndex (x);
            }
        }
    }

    return getTotalNumChars();
}

//==============================================================================
int TextEditor::findWordBreakAfter (const int position) const
{
    auto t = getTextInRange ({ position, position + 512 });
    auto totalLength = t.length();
    int i = 0;

    while (i < totalLength && CharacterFunctions::isWhitespace (t[i]))
        ++i;

    auto type = TextEditorDefs::getCharacterCategory (t[i]);

    while (i < totalLength && type == TextEditorDefs::getCharacterCategory (t[i]))
        ++i;

    while (i < totalLength && CharacterFunctions::isWhitespace (t[i]))
        ++i;

    return position + i;
}

int TextEditor::findWordBreakBefore (const int position) const
{
    if (position <= 0)
        return 0;

    auto startOfBuffer = jmax (0, position - 512);
    auto t = getTextInRange ({ startOfBuffer, position });

    int i = position - startOfBuffer;

    while (i > 0 && CharacterFunctions::isWhitespace (t [i - 1]))
        --i;

    if (i > 0)
    {
        auto type = TextEditorDefs::getCharacterCategory (t [i - 1]);

        while (i > 0 && type == TextEditorDefs::getCharacterCategory (t [i - 1]))
            --i;
    }

    jassert (startOfBuffer + i >= 0);
    return startOfBuffer + i;
}


//==============================================================================
void TextEditor::splitSection (const int sectionIndex, const int charToSplitAt)
{
    jassert (sections[sectionIndex] != nullptr);

    sections.insert (sectionIndex + 1,
                     sections.getUnchecked (sectionIndex)->split (charToSplitAt));
}

void TextEditor::coalesceSimilarSections()
{
    for (int i = 0; i < sections.size() - 1; ++i)
    {
        auto* s1 = sections.getUnchecked (i);
        auto* s2 = sections.getUnchecked (i + 1);

        if (s1->font == s2->font
             && s1->colour == s2->colour)
        {
            s1->append (*s2);
            sections.remove (i + 1);
            --i;
        }
    }
}

} // namespace juce