1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include "utils/Macros.h"
20 
21 #include <utils/Timers.h>
22 
23 #include <string>
24 
25 namespace android {
26 namespace uirenderer {
27 
28 namespace renderthread {
29 class CanvasContext;
30 }
31 
32 class DamageAccumulator;
33 class LayerUpdateQueue;
34 class RenderNode;
35 class RenderState;
36 
37 class ErrorHandler {
38 public:
39     virtual void onError(const std::string& message) = 0;
40 protected:
~ErrorHandler()41     ~ErrorHandler() {}
42 };
43 
44 class TreeObserver {
45 public:
46     // Called when a RenderNode's parent count hits 0.
47     // Due to the unordered nature of tree pushes, once prepareTree
48     // is finished it is possible that the node was "resurrected" and has
49     // a non-zero parent count.
50     virtual void onMaybeRemovedFromTree(RenderNode* node) = 0;
51 protected:
~TreeObserver()52     virtual ~TreeObserver() {}
53 };
54 
55 // This would be a struct, but we want to PREVENT_COPY_AND_ASSIGN
56 class TreeInfo {
57     PREVENT_COPY_AND_ASSIGN(TreeInfo);
58 public:
59     enum TraversalMode {
60         // The full monty - sync, push, run animators, etc... Used by DrawFrameTask
61         // May only be used if both the UI thread and RT thread are blocked on the
62         // prepare
63         MODE_FULL,
64         // Run only what can be done safely on RT thread. Currently this only means
65         // animators, but potentially things like SurfaceTexture updates
66         // could be handled by this as well if there are no listeners
67         MODE_RT_ONLY,
68     };
69 
TreeInfo(TraversalMode mode,renderthread::CanvasContext & canvasContext)70     TreeInfo(TraversalMode mode, renderthread::CanvasContext& canvasContext)
71             : mode(mode)
72             , prepareTextures(mode == MODE_FULL)
73             , canvasContext(canvasContext)
74     {}
75 
76     TraversalMode mode;
77     // TODO: Remove this? Currently this is used to signal to stop preparing
78     // textures if we run out of cache space.
79     bool prepareTextures;
80     renderthread::CanvasContext& canvasContext;
81     // TODO: buildLayer uses this to suppress running any animations, but this
82     // should probably be refactored somehow. The reason this is done is
83     // because buildLayer is not setup for injecting the animationHook, as well
84     // as this being otherwise wasted work as all the animators will be
85     // re-evaluated when the frame is actually drawn
86     bool runAnimations = true;
87 
88     // Must not be null during actual usage
89     DamageAccumulator* damageAccumulator = nullptr;
90 
91     LayerUpdateQueue* layerUpdateQueue = nullptr;
92     ErrorHandler* errorHandler = nullptr;
93 
94     bool updateWindowPositions = false;
95 
96     struct Out {
97         bool hasFunctors = false;
98         // This is only updated if evaluateAnimations is true
99         bool hasAnimations = false;
100         // This is set to true if there is an animation that RenderThread cannot
101         // animate itself, such as if hasFunctors is true
102         // This is only set if hasAnimations is true
103         bool requiresUiRedraw = false;
104         // This is set to true if draw() can be called this frame
105         // false means that we must delay until the next vsync pulse as frame
106         // production is outrunning consumption
107         // NOTE that if this is false CanvasContext will set either requiresUiRedraw
108         // *OR* will post itself for the next vsync automatically, use this
109         // only to avoid calling draw()
110         bool canDrawThisFrame = true;
111     } out;
112 
113     // This flag helps to disable projection for receiver nodes that do not have any backward
114     // projected children.
115     bool hasBackwardProjectedNodes = false;
116     // TODO: Damage calculations
117 };
118 
119 } /* namespace uirenderer */
120 } /* namespace android */
121