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      1 /*
      2 * Copyright 2017 Google Inc.
      3 *
      4 * Use of this source code is governed by a BSD-style license that can be
      5 * found in the LICENSE file.
      6 */
      7 
      8 #include "HelloWorld.h"
      9 
     10 #include "GrContext.h"
     11 #include "SkCanvas.h"
     12 #include "SkGradientShader.h"
     13 #include "SkGraphics.h"
     14 
     15 using namespace sk_app;
     16 
     17 Application* Application::Create(int argc, char** argv, void* platformData) {
     18     return new HelloWorld(argc, argv, platformData);
     19 }
     20 
     21 HelloWorld::HelloWorld(int argc, char** argv, void* platformData)
     22         : fBackendType(Window::kNativeGL_BackendType)
     23         , fRotationAngle(0) {
     24     SkGraphics::Init();
     25 
     26     fWindow = Window::CreateNativeWindow(platformData);
     27     fWindow->setRequestedDisplayParams(DisplayParams());
     28 
     29     // register callbacks
     30     fWindow->pushLayer(this);
     31 
     32     fWindow->attach(fBackendType);
     33 }
     34 
     35 HelloWorld::~HelloWorld() {
     36     fWindow->detach();
     37     delete fWindow;
     38 }
     39 
     40 void HelloWorld::updateTitle() {
     41     if (!fWindow || fWindow->sampleCount() <= 1) {
     42         return;
     43     }
     44 
     45     SkString title("Hello World ");
     46     title.append(Window::kRaster_BackendType == fBackendType ? "Raster" : "OpenGL");
     47     fWindow->setTitle(title.c_str());
     48 }
     49 
     50 void HelloWorld::onBackendCreated() {
     51     this->updateTitle();
     52     fWindow->show();
     53     fWindow->inval();
     54 }
     55 
     56 void HelloWorld::onPaint(SkCanvas* canvas) {
     57     // Clear background
     58     canvas->clear(SK_ColorWHITE);
     59 
     60     SkPaint paint;
     61     paint.setColor(SK_ColorRED);
     62 
     63     // Draw a rectangle with red paint
     64     SkRect rect = SkRect::MakeXYWH(10, 10, 128, 128);
     65     canvas->drawRect(rect, paint);
     66 
     67     // Set up a linear gradient and draw a circle
     68     {
     69         SkPoint linearPoints[] = { { 0, 0 }, { 300, 300 } };
     70         SkColor linearColors[] = { SK_ColorGREEN, SK_ColorBLACK };
     71         paint.setShader(SkGradientShader::MakeLinear(linearPoints, linearColors, nullptr, 2,
     72                                                      SkShader::kMirror_TileMode));
     73         paint.setAntiAlias(true);
     74 
     75         canvas->drawCircle(200, 200, 64, paint);
     76 
     77         // Detach shader
     78         paint.setShader(nullptr);
     79     }
     80 
     81     // Draw a message with a nice black paint
     82     paint.setSubpixelText(true);
     83     paint.setColor(SK_ColorBLACK);
     84     paint.setTextSize(20);
     85 
     86     canvas->save();
     87     static const char message[] = "Hello World";
     88 
     89     // Translate and rotate
     90     canvas->translate(300, 300);
     91     fRotationAngle += 0.2f;
     92     if (fRotationAngle > 360) {
     93         fRotationAngle -= 360;
     94     }
     95     canvas->rotate(fRotationAngle);
     96 
     97     // Draw the text
     98     canvas->drawText(message, strlen(message), 0, 0, paint);
     99 
    100     canvas->restore();
    101 }
    102 
    103 void HelloWorld::onIdle() {
    104     // Just re-paint continously
    105     fWindow->inval();
    106 }
    107 
    108 bool HelloWorld::onChar(SkUnichar c, uint32_t modifiers) {
    109     if (' ' == c) {
    110         fBackendType = Window::kRaster_BackendType == fBackendType ? Window::kNativeGL_BackendType
    111                                                                    : Window::kRaster_BackendType;
    112         fWindow->detach();
    113         fWindow->attach(fBackendType);
    114     }
    115     return true;
    116 }
    117