JUCE/modules/juce_gui_basics/widgets/juce_Label.cpp

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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   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
{

Label::Label (const String& name, const String& labelText)
    : Component (name),
      textValue (labelText),
      lastTextValue (labelText)
{
    setColour (TextEditor::textColourId, Colours::black);
    setColour (TextEditor::backgroundColourId, Colours::transparentBlack);
    setColour (TextEditor::outlineColourId, Colours::transparentBlack);

    textValue.addListener (this);
}

Label::~Label()
{
    textValue.removeListener (this);

    if (ownerComponent != nullptr)
        ownerComponent->removeComponentListener (this);

    editor.reset();
}

//==============================================================================
void Label::setText (const String& newText, NotificationType notification)
{
    hideEditor (true);

    if (lastTextValue != newText)
    {
        lastTextValue = newText;
        textValue = newText;
        repaint();

        textWasChanged();

        if (ownerComponent != nullptr)
            componentMovedOrResized (*ownerComponent, true, true);

        if (notification != dontSendNotification)
            callChangeListeners();
    }
}

String Label::getText (bool returnActiveEditorContents) const
{
    return (returnActiveEditorContents && isBeingEdited())
                ? editor->getText()
                : textValue.toString();
}

void Label::valueChanged (Value&)
{
    if (lastTextValue != textValue.toString())
        setText (textValue.toString(), sendNotification);
}

//==============================================================================
void Label::setFont (const Font& newFont)
{
    if (font != newFont)
    {
        font = newFont;
        repaint();
    }
}

Font Label::getFont() const noexcept
{
    return font;
}

void Label::setEditable (bool editOnSingleClick,
                         bool editOnDoubleClick,
                         bool lossOfFocusDiscards)
{
    editSingleClick = editOnSingleClick;
    editDoubleClick = editOnDoubleClick;
    lossOfFocusDiscardsChanges = lossOfFocusDiscards;

    setWantsKeyboardFocus (editOnSingleClick || editOnDoubleClick);
    setFocusContainer (editOnSingleClick || editOnDoubleClick);
}

void Label::setJustificationType (Justification newJustification)
{
    if (justification != newJustification)
    {
        justification = newJustification;
        repaint();
    }
}

void Label::setBorderSize (BorderSize<int> newBorder)
{
    if (border != newBorder)
    {
        border = newBorder;
        repaint();
    }
}

//==============================================================================
Component* Label::getAttachedComponent() const
{
    return ownerComponent.get();
}

void Label::attachToComponent (Component* owner, bool onLeft)
{
    jassert (owner != this); // Not a great idea to try to attach it to itself!

    if (ownerComponent != nullptr)
        ownerComponent->removeComponentListener (this);

    ownerComponent = owner;
    leftOfOwnerComp = onLeft;

    if (ownerComponent != nullptr)
    {
        setVisible (owner->isVisible());
        ownerComponent->addComponentListener (this);
        componentParentHierarchyChanged (*ownerComponent);
        componentMovedOrResized (*ownerComponent, true, true);
    }
}

void Label::componentMovedOrResized (Component& component, bool /*wasMoved*/, bool /*wasResized*/)
{
    auto& lf = getLookAndFeel();
    auto f = lf.getLabelFont (*this);
    auto borderSize = lf.getLabelBorderSize (*this);

    if (leftOfOwnerComp)
    {
        auto width = jmin (roundToInt (f.getStringWidthFloat (textValue.toString()) + 0.5f)
                             + borderSize.getLeftAndRight(),
                           component.getX());

        setBounds (component.getX() - width, component.getY(), width, component.getHeight());
    }
    else
    {
        auto height = borderSize.getTopAndBottom() + 6 + roundToInt (f.getHeight() + 0.5f);

        setBounds (component.getX(), component.getY() - height, component.getWidth(), height);
    }
}

void Label::componentParentHierarchyChanged (Component& component)
{
    if (auto* parent = component.getParentComponent())
        parent->addChildComponent (this);
}

void Label::componentVisibilityChanged (Component& component)
{
    setVisible (component.isVisible());
}

//==============================================================================
void Label::textWasEdited() {}
void Label::textWasChanged() {}

void Label::editorShown (TextEditor* textEditor)
{
    Component::BailOutChecker checker (this);
    listeners.callChecked (checker, [this, textEditor] (Label::Listener& l) { l.editorShown (this, *textEditor); });

    if (checker.shouldBailOut())
        return;

    if (onEditorShow != nullptr)
        onEditorShow();
}

void Label::editorAboutToBeHidden (TextEditor* textEditor)
{
    if (auto* peer = getPeer())
        peer->dismissPendingTextInput();

    Component::BailOutChecker checker (this);
    listeners.callChecked (checker, [this, textEditor] (Label::Listener& l) { l.editorHidden (this, *textEditor); });

    if (checker.shouldBailOut())
        return;

    if (onEditorHide != nullptr)
        onEditorHide();
}

void Label::showEditor()
{
    if (editor == nullptr)
    {
        editor.reset (createEditorComponent());
        addAndMakeVisible (editor.get());
        editor->setText (getText(), false);
        editor->setKeyboardType (keyboardType);
        editor->addListener (this);
        editor->grabKeyboardFocus();

        if (editor == nullptr) // may be deleted by a callback
            return;

        editor->setHighlightedRegion (Range<int> (0, textValue.toString().length()));

        resized();
        repaint();

        editorShown (editor.get());

        enterModalState (false);
        editor->grabKeyboardFocus();
    }
}

bool Label::updateFromTextEditorContents (TextEditor& ed)
{
    auto newText = ed.getText();

    if (textValue.toString() != newText)
    {
        lastTextValue = newText;
        textValue = newText;
        repaint();

        textWasChanged();

        if (ownerComponent != nullptr)
            componentMovedOrResized (*ownerComponent, true, true);

        return true;
    }

    return false;
}

void Label::hideEditor (bool discardCurrentEditorContents)
{
    if (editor != nullptr)
    {
        WeakReference<Component> deletionChecker (this);
        std::unique_ptr<TextEditor> outgoingEditor;
        std::swap (outgoingEditor, editor);

        editorAboutToBeHidden (outgoingEditor.get());

        const bool changed = (! discardCurrentEditorContents)
                               && updateFromTextEditorContents (*outgoingEditor);
        outgoingEditor.reset();
        repaint();

        if (changed)
            textWasEdited();

        if (deletionChecker != nullptr)
            exitModalState (0);

        if (changed && deletionChecker != nullptr)
            callChangeListeners();
    }
}

void Label::inputAttemptWhenModal()
{
    if (editor != nullptr)
    {
        if (lossOfFocusDiscardsChanges)
            textEditorEscapeKeyPressed (*editor);
        else
            textEditorReturnKeyPressed (*editor);
    }
}

bool Label::isBeingEdited() const noexcept
{
    return editor != nullptr;
}

static void copyColourIfSpecified (Label& l, TextEditor& ed, int colourID, int targetColourID)
{
    if (l.isColourSpecified (colourID) || l.getLookAndFeel().isColourSpecified (colourID))
        ed.setColour (targetColourID, l.findColour (colourID));
}

TextEditor* Label::createEditorComponent()
{
    auto* ed = new TextEditor (getName());
    ed->applyFontToAllText (getLookAndFeel().getLabelFont (*this));
    copyAllExplicitColoursTo (*ed);

    copyColourIfSpecified (*this, *ed, textWhenEditingColourId, TextEditor::textColourId);
    copyColourIfSpecified (*this, *ed, backgroundWhenEditingColourId, TextEditor::backgroundColourId);
    copyColourIfSpecified (*this, *ed, outlineWhenEditingColourId, TextEditor::focusedOutlineColourId);

    return ed;
}

TextEditor* Label::getCurrentTextEditor() const noexcept
{
    return editor.get();
}

//==============================================================================
void Label::paint (Graphics& g)
{
    getLookAndFeel().drawLabel (g, *this);
}

void Label::mouseUp (const MouseEvent& e)
{
    if (editSingleClick
         && isEnabled()
         && contains (e.getPosition())
         && ! (e.mouseWasDraggedSinceMouseDown() || e.mods.isPopupMenu()))
    {
        showEditor();
    }
}

void Label::mouseDoubleClick (const MouseEvent& e)
{
    if (editDoubleClick
         && isEnabled()
         && ! e.mods.isPopupMenu())
        showEditor();
}

void Label::resized()
{
    if (editor != nullptr)
        editor->setBounds (getLocalBounds());
}

void Label::focusGained (FocusChangeType cause)
{
    if (editSingleClick
         && isEnabled()
         && cause == focusChangedByTabKey)
        showEditor();
}

void Label::enablementChanged()
{
    repaint();
}

void Label::colourChanged()
{
    repaint();
}

void Label::setMinimumHorizontalScale (const float newScale)
{
    if (minimumHorizontalScale != newScale)
    {
        minimumHorizontalScale = newScale;
        repaint();
    }
}

//==============================================================================
// We'll use a custom focus traverser here to make sure focus goes from the
// text editor to another component rather than back to the label itself.
class LabelKeyboardFocusTraverser   : public KeyboardFocusTraverser
{
public:
    LabelKeyboardFocusTraverser() {}

    Component* getNextComponent (Component* c) override     { return KeyboardFocusTraverser::getNextComponent (getComp (c)); }
    Component* getPreviousComponent (Component* c) override { return KeyboardFocusTraverser::getPreviousComponent (getComp (c)); }

    static Component* getComp (Component* current)
    {
        return dynamic_cast<TextEditor*> (current) != nullptr
                 ? current->getParentComponent() : current;
    }
};

KeyboardFocusTraverser* Label::createFocusTraverser()
{
    return new LabelKeyboardFocusTraverser();
}

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

void Label::callChangeListeners()
{
    Component::BailOutChecker checker (this);
    listeners.callChecked (checker, [this] (Listener& l) { l.labelTextChanged (this); });

    if (checker.shouldBailOut())
        return;

    if (onTextChange != nullptr)
        onTextChange();
}

//==============================================================================
void Label::textEditorTextChanged (TextEditor& ed)
{
    if (editor != nullptr)
    {
        jassert (&ed == editor.get());

        if (! (hasKeyboardFocus (true) || isCurrentlyBlockedByAnotherModalComponent()))
        {
            if (lossOfFocusDiscardsChanges)
                textEditorEscapeKeyPressed (ed);
            else
                textEditorReturnKeyPressed (ed);
        }
    }
}

void Label::textEditorReturnKeyPressed (TextEditor& ed)
{
    if (editor != nullptr)
    {
        jassert (&ed == editor.get());

        WeakReference<Component> deletionChecker (this);
        bool changed = updateFromTextEditorContents (ed);
        hideEditor (true);

        if (changed && deletionChecker != nullptr)
        {
            textWasEdited();

            if (deletionChecker != nullptr)
                callChangeListeners();
        }
    }
}

void Label::textEditorEscapeKeyPressed (TextEditor& ed)
{
    if (editor != nullptr)
    {
        jassert (&ed == editor.get());
        ignoreUnused (ed);

        editor->setText (textValue.toString(), false);
        hideEditor (true);
    }
}

void Label::textEditorFocusLost (TextEditor& ed)
{
    textEditorTextChanged (ed);
}

} // namespace juce