xref: /aosp_15_r20/external/skia/tools/skottie_ios_app/SkiaUIContext.mm (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1// Copyright 2020 Google LLC.
2// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3
4#include "tools/skottie_ios_app/SkiaContext.h"
5
6#include "include/core/SkBitmap.h"
7#include "include/core/SkCanvas.h"
8#include "include/core/SkSize.h"
9#include "include/utils/mac/SkCGUtils.h"
10#include "src/base/SkTime.h"
11
12#import <UIKit/UIKit.h>
13
14// A UIView that uses a CPU-backed SkSurface to draw.
15@interface SkiaUIView : UIView
16    @property (strong) SkiaViewController* controller;
17
18    // Override of the UIView interface.
19    - (void)drawRect:(CGRect)rect;
20@end
21
22@implementation SkiaUIView {
23    SkBitmap fBackBuffer;
24}
25
26- (void)drawRect:(CGRect)rect {
27    SkiaViewController* viewController = [self controller];
28    static constexpr double kFrameRate = 1.0 / 30.0;
29    double next = [viewController isPaused] ? 0 : kFrameRate + SkTime::GetNSecs() * 1e-9;
30    [super drawRect:rect];
31    CGSize size = [self bounds].size;
32    SkISize iSize = {(int)size.width, (int)size.height};
33    if (fBackBuffer.drawsNothing() || iSize != fBackBuffer.dimensions()) {
34        fBackBuffer.allocN32Pixels(iSize.fWidth, iSize.fHeight);
35    }
36    fBackBuffer.eraseColor(SK_ColorTRANSPARENT);
37    {
38        SkCanvas canvas(fBackBuffer);
39        [viewController draw:rect toCanvas:&canvas atSize:size];
40    }
41    SkCGDrawBitmap(UIGraphicsGetCurrentContext(), fBackBuffer, 0, 0);
42    if (next) {
43        [NSTimer scheduledTimerWithTimeInterval:std::max(0.0, next - SkTime::GetNSecs() * 1e-9)
44                 target:self
45                 selector:@selector(setNeedsDisplay)
46                 userInfo:nil
47                 repeats:NO];
48    }
49}
50@end
51
52@interface SkiaUIContext : SkiaContext
53    - (UIView*) makeViewWithController:(SkiaViewController*)vc withFrame:(CGRect)frame;
54    - (SkiaViewController*) getViewController:(UIView*)view;
55@end
56
57@implementation SkiaUIContext
58- (UIView*) makeViewWithController:(SkiaViewController*)vc withFrame:(CGRect)frame {
59    SkiaUIView* skiaView = [[SkiaUIView alloc] initWithFrame:frame];
60    [skiaView setController:vc];
61    return skiaView;
62}
63- (SkiaViewController*) getViewController:(UIView*)view {
64    return [view isKindOfClass:[SkiaUIView class]] ? [(SkiaUIView*)view controller] : nil;
65}
66@end
67
68SkiaContext* MakeSkiaUIContext() { return [[SkiaUIContext alloc] init]; }
69