skia2/samplecode/Sample.h
Ben Wagner cad130bd36 Ensure Sample::onOnceBeforeDraw before onAnimate.
On Linux, Viewer can sometimes attempt to animate a sample before the
first time it is drawn. If the sample's onAnimate depends on resources
being loaded in onOnceBeforeDraw then it may crash.

Change-Id: Idddf3dc80e2ee2bc3252cc3ee58784d14165bc07
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/518136
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Ben Wagner <bungeman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2022-03-08 21:50:17 +00:00

107 lines
3.2 KiB
C++

/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SampleCode_DEFINED
#define SampleCode_DEFINED
#include "include/core/SkColor.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkString.h"
#include "include/private/SkMacros.h"
#include "tools/Registry.h"
#include "tools/SkMetaData.h"
#include "tools/skui/InputState.h"
#include "tools/skui/ModifierKey.h"
#include <functional>
class SkCanvas;
class Sample;
using SampleFactory = Sample* (*)();
using SampleRegistry = sk_tools::Registry<SampleFactory>;
#define DEF_SAMPLE(code) \
static Sample* SK_MACRO_APPEND_LINE(F_)() { code } \
static SampleRegistry SK_MACRO_APPEND_LINE(R_)(SK_MACRO_APPEND_LINE(F_));
///////////////////////////////////////////////////////////////////////////////
class Sample {
public:
Sample()
: fBGColor(SK_ColorWHITE)
, fWidth(0), fHeight(0)
, fHaveCalledOnceBeforeDraw(false)
{}
virtual ~Sample() = default;
SkScalar width() const { return fWidth; }
SkScalar height() const { return fHeight; }
void setSize(SkScalar width, SkScalar height);
void setSize(const SkPoint& size) { this->setSize(size.fX, size.fY); }
void setWidth(SkScalar width) { this->setSize(width, fHeight); }
void setHeight(SkScalar height) { this->setSize(fWidth, height); }
/** Call this to have the view draw into the specified canvas. */
virtual void draw(SkCanvas* canvas);
virtual bool onChar(SkUnichar) { return false; }
// Click handling
class Click {
public:
Click() {}
Click(std::function<bool(Click*)> f) : fFunc(f), fHasFunc(true) {}
virtual ~Click() = default;
SkPoint fOrig = {0, 0};
SkPoint fPrev = {0, 0};
SkPoint fCurr = {0, 0};
skui::InputState fState = skui::InputState::kDown;
skui::ModifierKey fModifierKeys = skui::ModifierKey::kNone;
SkMetaData fMeta;
std::function<bool(Click*)> fFunc;
bool fHasFunc = false;
};
bool mouse(SkPoint point, skui::InputState clickState, skui::ModifierKey modifierKeys);
void setBGColor(SkColor color) { fBGColor = color; }
bool animate(double nanos);
virtual SkString name() = 0;
protected:
/** Override to be notified of size changes. Overriders must call the super class. */
virtual void onSizeChange();
/** Override this if you might handle the click */
virtual Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey modi);
/** Override to track clicks. Return true as long as you want to track the pen/mouse. */
virtual bool onClick(Click*);
virtual void onDrawBackground(SkCanvas*);
virtual void onDrawContent(SkCanvas*) = 0;
virtual bool onAnimate(double /*nanos*/) { return false; }
virtual void onOnceBeforeDraw() {}
private:
std::unique_ptr<Click> fClick;
SkColor fBGColor;
SkScalar fWidth, fHeight;
bool fHaveCalledOnceBeforeDraw;
Sample(const Sample&) = delete;
Sample& operator=(const Sample&) = delete;
};
#endif