1 /*
2  * Copyright (c) 2021 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef FOUNDATION_ACE_FRAMEWORKS_CORE_COMPONENTS_BASE_SCOPED_CANVAS_STATE_H
17 #define FOUNDATION_ACE_FRAMEWORKS_CORE_COMPONENTS_BASE_SCOPED_CANVAS_STATE_H
18 
19 #include "core/pipeline/base/flutter_render_context.h"
20 
21 namespace OHOS::Ace {
22 
23 class ScopedCanvas final {
24 public:
Create(RenderContext & context)25     static ScopedCanvas Create(RenderContext& context)
26     {
27         auto renderContext = AceType::DynamicCast<FlutterRenderContext>(&context);
28         if (!renderContext) {
29             LOGE("render context is null");
30             return ScopedCanvas(nullptr);
31         }
32         auto canvas = renderContext->GetCanvas();
33         if (!canvas) {
34             LOGE("Paint canvas is null");
35             return ScopedCanvas(nullptr);
36         }
37         return ScopedCanvas(canvas);
38     }
39 
ScopedCanvas(flutter::Canvas * canvas)40     explicit ScopedCanvas(flutter::Canvas* canvas) : canvas_(canvas)
41     {
42         if (canvas_ != nullptr) {
43             canvas_->save();
44         }
45     }
46 
~ScopedCanvas()47     ~ScopedCanvas()
48     {
49         if (canvas_) {
50             canvas_->restore();
51         }
52     }
53 
54     // Need to check with bool function before call this function.
55     flutter::Canvas* operator->() const
56     {
57         return canvas_;
58     }
59 
60     operator bool() const
61     {
62         return canvas_ != nullptr;
63     }
64 
GetSkCanvas()65     SkCanvas* GetSkCanvas()
66     {
67         if (canvas_) {
68             return canvas_->canvas();
69         }
70         return nullptr;
71     }
72 
FlipHorizontal(double horizontalOffset,double drawRectWidth)73     void FlipHorizontal(double horizontalOffset, double drawRectWidth) const
74     {
75         double horizontalMoveDelta = -1.0 * (horizontalOffset + drawRectWidth / 2.0);
76         canvas_->translate(-1.0 * horizontalMoveDelta, 0.0);
77         canvas_->scale(-1.0, 1.0);
78         canvas_->translate(horizontalMoveDelta, 0.0);
79     }
80 
81 private:
82     flutter::Canvas* canvas_ = nullptr;
83 
84     ACE_DISALLOW_COPY_AND_MOVE(ScopedCanvas);
85 };
86 
87 } // namespace OHOS::Ace
88 
89 #endif // FOUNDATION_ACE_FRAMEWORKS_CORE_COMPONENTS_BASE_SCOPED_CANVAS_STATE_H
90