#Topic Automatic_Canvas_Restore
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#Class SkAutoCanvasRestore
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#Code
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#Populate
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##
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Stack helper class calls SkCanvas::restoreToCount when SkAutoCanvasRestore
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goes out of scope. Use this to guarantee that the canvas is restored to a known
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state.
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#Method SkAutoCanvasRestore(SkCanvas* canvas, bool doSave)
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#Line # restores Canvas when out of scope ##
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#Populate
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#Example
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#Height 128
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SkPaint p;
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SkFont font(nullptr, 64);
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for (SkScalar sx : { -1, 1 } ) {
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for (SkScalar sy : { -1, 1 } ) {
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SkAutoCanvasRestore autoRestore(canvas, true);
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SkMatrix m = SkMatrix::MakeAll(sx, 1, 96, 0, sy, 64, 0, 0, 1);
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canvas->concat(m);
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canvas->drawString("R", 0, 0, font, p);
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}
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}
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##
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#SeeAlso SkCanvas::save SkCanvas::restore
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##
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#Method ~SkAutoCanvasRestore()
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#Line # restores Canvas to saved state ##
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#Populate
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#NoExample
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##
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#SeeAlso SkCanvas::save SkCanvas::restore
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##
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#Method void restore()
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#In Member_Function
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#Line # restores Canvas to saved state ##
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#Populate
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#Example
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for (bool callRestore : { false, true } ) {
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for (bool saveCanvas : {false, true} ) {
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SkAutoCanvasRestore autoRestore(canvas, saveCanvas);
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if (!saveCanvas) {
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canvas->save();
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}
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SkDebugf("saveCanvas: %s before restore: %d\n",
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saveCanvas ? "true" : "false", canvas->getSaveCount());
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if (callRestore) autoRestore.restore();
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SkDebugf("saveCanvas: %s after restore: %d\n",
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saveCanvas ? "true" : "false", canvas->getSaveCount());
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}
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}
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SkDebugf("final count: %d\n", canvas->getSaveCount());
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#StdOut
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saveCanvas: false before restore: 2
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saveCanvas: false after restore: 2
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saveCanvas: true before restore: 2
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saveCanvas: true after restore: 2
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saveCanvas: false before restore: 2
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saveCanvas: false after restore: 1
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saveCanvas: true before restore: 2
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saveCanvas: true after restore: 1
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final count: 1
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##
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##
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#SeeAlso SkCanvas::save SkCanvas::restore
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##
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#Class SkAutoCanvasRestore ##
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#Topic Automatic_Canvas_Restore ##
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