source/modules/juce_gui_basics/misc/juce_FocusOutline.h

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library.
   5    Copyright (c) 2022 - Raw Material Software Limited
   6
   7    JUCE is an open source library subject to commercial or open-source
   8    licensing.
   9
  10    By using JUCE, you agree to the terms of both the JUCE 7 End-User License
  11    Agreement and JUCE Privacy Policy.
  12
  13    End User License Agreement: www.juce.com/juce-7-licence
  14    Privacy Policy: www.juce.com/juce-privacy-policy
  15
  16    Or: You may also use this code under the terms of the GPL v3 (see
  17    www.gnu.org/licenses).
  18
  19    JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
  20    EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
  21    DISCLAIMED.
  22
  23   ==============================================================================
  24 */
  25
  26 namespace juce
  27 {
  28
  29 /**
  30     Adds a focus outline to a component.
  31
  32     This object creates and manages a component that sits on top of a target
  33     component. It will track the position of the target component and will be
  34     brought to the front with the tracked component.
  35
  36     Use the Component::setHasFocusOutline() method to indicate that a component
  37     should have a focus outline drawn around it, and when it receives keyboard
  38     focus one of these objects will be created using the
  39     LookAndFeel::createFocusOutlineForComponent() method. You can override this
  40     method in your own LookAndFeel classes to draw a custom outline if required.
  41
  42     @tags{GUI}
  43 */
  44 class JUCE_API  FocusOutline  : private ComponentListener
  45 {
  46 public:
  47     //==============================================================================
  48     /** Defines the focus outline window properties.
  49
  50         Pass an instance of one of these to the FocusOutline constructor to control
  51         the bounds for the outline window and how it is drawn.
  52     */
  53     struct JUCE_API  OutlineWindowProperties
  54     {
  55         virtual ~OutlineWindowProperties() = default;
  56
  57         /** Return the bounds for the outline window in screen coordinates. */
  58         virtual Rectangle<int> getOutlineBounds (Component& focusedComponent) = 0;
  59
  60         /** This method will be called to draw the focus outline. */
  61         virtual void drawOutline (Graphics&, int width, int height) = 0;
  62     };
  63
  64     //==============================================================================
  65     /** Creates a FocusOutline.
  66
  67         Call setOwner to attach it to a component.
  68     */
  69     FocusOutline (std::unique_ptr<OutlineWindowProperties> props);
  70
  71     /** Destructor. */
  72     ~FocusOutline() override;
  73
  74     /** Attaches the outline to a component. */
  75     void setOwner (Component* componentToFollow);
  76
  77 private:
  78     //==============================================================================
  79     void componentMovedOrResized (Component&, bool, bool) override;
  80     void componentBroughtToFront (Component&) override;
  81     void componentParentHierarchyChanged (Component&) override;
  82     void componentVisibilityChanged (Component&) override;
  83
  84     void updateOutlineWindow();
  85     void updateParent();
  86
  87     //==============================================================================
  88     std::unique_ptr<OutlineWindowProperties> properties;
  89
  90     WeakReference<Component> owner;
  91     std::unique_ptr<Component> outlineWindow;
  92     WeakReference<Component> lastParentComp;
  93
  94     bool reentrant = false;
  95
  96     //==============================================================================
  97     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (FocusOutline)
  98 };
  99
 100 } // namespace juce