1 /*
2   ==============================================================================
3 
4    This file is part of the JUCE library.
5    Copyright (c) 2020 - 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 6 End-User License
11    Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
12 
13    End User License Agreement: www.juce.com/juce-6-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 /**
31     Base class used internally for structures that can store cached images of
32     component state.
33 
34     Most people are unlikely to ever need to know about this class - it's really
35     only for power-users!
36 
37     @see Component::setCachedComponentImage
38 
39     @tags{GUI}
40 */
41 class JUCE_API  CachedComponentImage
42 {
43 public:
44     CachedComponentImage() = default;
45     virtual ~CachedComponentImage() = default;
46 
47     //==============================================================================
48     /** Called as part of the parent component's paint method, this must draw
49         the given component into the target graphics context, using the cached
50         version where possible.
51     */
52     virtual void paint (Graphics&) = 0;
53 
54     /** Invalidates all cached image data.
55         @returns true if the peer should also be repainted, or false if this object
56                  handles all repaint work internally.
57     */
58     virtual bool invalidateAll() = 0;
59 
60     /** Invalidates a section of the cached image data.
61         @returns true if the peer should also be repainted, or false if this object
62                  handles all repaint work internally.
63     */
64     virtual bool invalidate (const Rectangle<int>& area) = 0;
65 
66     /** Called to indicate that the component is no longer active, so
67         any cached data should be released if possible.
68     */
69     virtual void releaseResources() = 0;
70 };
71 
72 } // namespace juce
73