JUCE/modules/juce_graphics/geometry/juce_BorderSize.h

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

   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
{

//==============================================================================
/**
    Specifies a set of gaps to be left around the sides of a rectangle.

    This is basically the size of the spaces at the top, bottom, left and right of
    a rectangle. It's used by various component classes to specify borders.

    @see Rectangle

    @tags{Graphics}
*/
template <typename ValueType>
class BorderSize
{
public:
    //==============================================================================
    /** Creates a null border.
        All sizes are left as 0.
    */
    BorderSize() = default;

    /** Creates a copy of another border. */
    BorderSize (const BorderSize&) = default;

    /** Creates a border with the given gaps. */
    BorderSize (ValueType topGap, ValueType leftGap, ValueType bottomGap, ValueType rightGap) noexcept
        : top (topGap), left (leftGap), bottom (bottomGap), right (rightGap)
    {
    }

    /** Creates a border with the given gap on all sides. */
    explicit BorderSize (ValueType allGaps) noexcept
        : top (allGaps), left (allGaps), bottom (allGaps), right (allGaps)
    {
    }

    //==============================================================================
    /** Returns the gap that should be left at the top of the region. */
    ValueType getTop() const noexcept                   { return top; }

    /** Returns the gap that should be left at the left of the region. */
    ValueType getLeft() const noexcept                  { return left; }

    /** Returns the gap that should be left at the bottom of the region. */
    ValueType getBottom() const noexcept                { return bottom; }

    /** Returns the gap that should be left at the right of the region. */
    ValueType getRight() const noexcept                 { return right; }

    /** Returns the sum of the top and bottom gaps. */
    ValueType getTopAndBottom() const noexcept          { return top + bottom; }

    /** Returns the sum of the left and right gaps. */
    ValueType getLeftAndRight() const noexcept          { return left + right; }

    /** Returns true if this border has no thickness along any edge. */
    bool isEmpty() const noexcept                       { return left + right + top + bottom == ValueType(); }

    //==============================================================================
    /** Changes the top gap. */
    void setTop (ValueType newTopGap) noexcept          { top = newTopGap; }

    /** Changes the left gap. */
    void setLeft (ValueType newLeftGap) noexcept        { left = newLeftGap; }

    /** Changes the bottom gap. */
    void setBottom (ValueType newBottomGap) noexcept    { bottom = newBottomGap; }

    /** Changes the right gap. */
    void setRight (ValueType newRightGap) noexcept      { right = newRightGap; }

    //==============================================================================
    /** Returns a rectangle with these borders removed from it. */
    Rectangle<ValueType> subtractedFrom (const Rectangle<ValueType>& original) const noexcept
    {
        return Rectangle<ValueType> (original.getX() + left,
                                     original.getY() + top,
                                     original.getWidth() - (left + right),
                                     original.getHeight() - (top + bottom));
    }

    /** Removes this border from a given rectangle. */
    void subtractFrom (Rectangle<ValueType>& rectangle) const noexcept
    {
        rectangle = subtractedFrom (rectangle);
    }

    /** Returns a rectangle with these borders added around it. */
    Rectangle<ValueType> addedTo (const Rectangle<ValueType>& original) const noexcept
    {
        return Rectangle<ValueType> (original.getX() - left,
                                     original.getY() - top,
                                     original.getWidth() + (left + right),
                                     original.getHeight() + (top + bottom));
    }


    /** Adds this border around a given rectangle. */
    void addTo (Rectangle<ValueType>& rectangle) const noexcept
    {
        rectangle = addedTo (rectangle);
    }

    //==============================================================================
    bool operator== (const BorderSize& other) const noexcept
    {
        return top == other.top && left == other.left && bottom == other.bottom && right == other.right;
    }

    bool operator!= (const BorderSize& other) const noexcept
    {
        return ! operator== (other);
    }

private:
    //==============================================================================
    ValueType top{}, left{}, bottom{}, right{};
};

} // namespace juce