juce/source/src/gui/components/layout/juce_ResizableBorderComponent.h

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library - "Jules' Utility Class Extensions"
   5    Copyright 2004-11 by Raw Material Software Ltd.
   6
   7   ------------------------------------------------------------------------------
   8
   9    JUCE can be redistributed and/or modified under the terms of the GNU General
  10    Public License (Version 2), as published by the Free Software Foundation.
  11    A copy of the license is included in the JUCE distribution, or can be found
  12    online at www.gnu.org/licenses.
  13
  14    JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
  15    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  16    A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  17
  18   ------------------------------------------------------------------------------
  19
  20    To release a closed-source product which uses JUCE, commercial licenses are
  21    available: visit www.rawmaterialsoftware.com/juce for more information.
  22
  23   ==============================================================================
  24 */
  25
  26 #ifndef __JUCE_RESIZABLEBORDERCOMPONENT_JUCEHEADER__
  27 #define __JUCE_RESIZABLEBORDERCOMPONENT_JUCEHEADER__
  28
  29 #include "juce_ComponentBoundsConstrainer.h"
  30
  31
  32 //==============================================================================
  33 /**
  34     A component that resizes its parent component when dragged.
  35
  36     This component forms a frame around the edge of a component, allowing it to
  37     be dragged by the edges or corners to resize it - like the way windows are
  38     resized in MSWindows or Linux.
  39
  40     To use it, just add it to your component, making it fill the entire parent component
  41     (there's a mouse hit-test that only traps mouse-events which land around the
  42     edge of the component, so it's even ok to put it on top of any other components
  43     you're using). Make sure you rescale the resizer component to fill the parent
  44     each time the parent's size changes.
  45
  46     @see ResizableCornerComponent
  47 */
  48 class JUCE_API  ResizableBorderComponent  : public Component
  49 {
  50 public:
  51     //==============================================================================
  52     /** Creates a resizer.
  53
  54         Pass in the target component which you want to be resized when this one is
  55         dragged.
  56
  57         The target component will usually be a parent of the resizer component, but this
  58         isn't mandatory.
  59
  60         Remember that when the target component is resized, it'll need to move and
  61         resize this component to keep it in place, as this won't happen automatically.
  62
  63         If the constrainer parameter is non-zero, then this object will be used to enforce
  64         limits on the size and position that the component can be stretched to. Make sure
  65         that the constrainer isn't deleted while still in use by this object.
  66
  67         @see ComponentBoundsConstrainer
  68     */
  69     ResizableBorderComponent (Component* componentToResize,
  70                               ComponentBoundsConstrainer* constrainer);
  71
  72     /** Destructor. */
  73     ~ResizableBorderComponent();
  74
  75
  76     //==============================================================================
  77     /** Specifies how many pixels wide the draggable edges of this component are.
  78
  79         @see getBorderThickness
  80     */
  81     void setBorderThickness (const BorderSize<int>& newBorderSize);
  82
  83     /** Returns the number of pixels wide that the draggable edges of this component are.
  84
  85         @see setBorderThickness
  86     */
  87     const BorderSize<int> getBorderThickness() const;
  88
  89
  90     //==============================================================================
  91     /** Represents the different sections of a resizable border, which allow it to
  92         resized in different ways.
  93     */
  94     class Zone
  95     {
  96     public:
  97         //==============================================================================
  98         enum Zones
  99         {
 100             centre  = 0,
 101             left    = 1,
 102             top     = 2,
 103             right   = 4,
 104             bottom  = 8
 105         };
 106
 107         //==============================================================================
 108         /** Creates a Zone from a combination of the flags in \enum Zones. */
 109         explicit Zone (int zoneFlags = 0) noexcept;
 110         Zone (const Zone& other) noexcept;
 111         Zone& operator= (const Zone& other) noexcept;
 112
 113         bool operator== (const Zone& other) const noexcept;
 114         bool operator!= (const Zone& other) const noexcept;
 115
 116         //==============================================================================
 117         /** Given a point within a rectangle with a resizable border, this returns the
 118             zone that the point lies within.
 119         */
 120         static const Zone fromPositionOnBorder (const Rectangle<int>& totalSize,
 121                                                 const BorderSize<int>& border,
 122                                                 const Point<int>& position);
 123
 124         /** Returns an appropriate mouse-cursor for this resize zone. */
 125         const MouseCursor getMouseCursor() const noexcept;
 126
 127         /** Returns true if dragging this zone will move the enire object without resizing it. */
 128         bool isDraggingWholeObject() const noexcept     { return zone == centre; }
 129         /** Returns true if dragging this zone will move the object's left edge. */
 130         bool isDraggingLeftEdge() const noexcept        { return (zone & left) != 0; }
 131         /** Returns true if dragging this zone will move the object's right edge. */
 132         bool isDraggingRightEdge() const noexcept       { return (zone & right) != 0; }
 133         /** Returns true if dragging this zone will move the object's top edge. */
 134         bool isDraggingTopEdge() const noexcept         { return (zone & top) != 0; }
 135         /** Returns true if dragging this zone will move the object's bottom edge. */
 136         bool isDraggingBottomEdge() const noexcept      { return (zone & bottom) != 0; }
 137
 138         /** Resizes this rectangle by the given amount, moving just the edges that this zone
 139             applies to.
 140         */
 141         template <typename ValueType>
 142         const Rectangle<ValueType> resizeRectangleBy (Rectangle<ValueType> original,
 143                                                       const Point<ValueType>& distance) const noexcept
 144         {
 145             if (isDraggingWholeObject())
 146                 return original + distance;
 147
 148             if (isDraggingLeftEdge())
 149                 original.setLeft (jmin (original.getRight(), original.getX() + distance.getX()));
 150
 151             if (isDraggingRightEdge())
 152                 original.setWidth (jmax (ValueType(), original.getWidth() + distance.getX()));
 153
 154             if (isDraggingTopEdge())
 155                 original.setTop (jmin (original.getBottom(), original.getY() + distance.getY()));
 156
 157             if (isDraggingBottomEdge())
 158                 original.setHeight (jmax (ValueType(), original.getHeight() + distance.getY()));
 159
 160             return original;
 161         }
 162
 163         /** Returns the raw flags for this zone. */
 164         int getZoneFlags() const noexcept               { return zone; }
 165
 166     private:
 167         //==============================================================================
 168         int zone;
 169     };
 170
 171
 172 protected:
 173     //==============================================================================
 174     /** @internal */
 175     void paint (Graphics& g);
 176     /** @internal */
 177     void mouseEnter (const MouseEvent& e);
 178     /** @internal */
 179     void mouseMove (const MouseEvent& e);
 180     /** @internal */
 181     void mouseDown (const MouseEvent& e);
 182     /** @internal */
 183     void mouseDrag (const MouseEvent& e);
 184     /** @internal */
 185     void mouseUp (const MouseEvent& e);
 186     /** @internal */
 187     bool hitTest (int x, int y);
 188
 189 private:
 190     WeakReference<Component> component;
 191     ComponentBoundsConstrainer* constrainer;
 192     BorderSize<int> borderSize;
 193     Rectangle<int> originalBounds;
 194     Zone mouseZone;
 195
 196     void updateMouseZone (const MouseEvent& e);
 197
 198     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ResizableBorderComponent);
 199 };
 200
 201
 202 #endif   // __JUCE_RESIZABLEBORDERCOMPONENT_JUCEHEADER__