touchGFX综合学习四、touchGFX使用SnapshotWidget进行截图

一、资源准备

准备一张图片：

二、touchGFX工程搭建

1、添加图片资源

2、控件放置

注意顺序哦

控件说明：

textArea1：滚动显示数字

imgBG：截图区域背景

image1：显示截图的内容

btnSnapshot：按下此按钮截图

3、interactions设置

三、工程源码修改

1、​​TouchGFXHAL.cpp​​

添加图片缓存区

void TouchGFXHAL::initialize()
{
    // Calling parent implementation of initialize().
    //
    // To overwrite the generated implementation, omit call to parent function
    // and implemented needed functionality here.
    // Please note, HAL::initialize() must be called to initialize the framework.

    TouchGFXGeneratedHAL::initialize();

    #define SDRAM_START_ADDR 0xc0000000
    uint32_t frame_size = DISPLAY_HEIGHT*DISPLAY_WIDTH*3;//一个帧缓冲区的大小
    setFrameBufferStartAddresses((void*)SDRAM_START_ADDR, (void*)(SDRAM_START_ADDR+frame_size), (void*)(SDRAM_START_ADDR+frame_size*2));//设置三级缓存地址,最后一级是开启动画功能的
    setFrameRateCompensation(true);//开启帧速率补偿,对动画有平滑的作用

    //图片缓存功能
    #define BITMAP_CACHE_SIZE   0x1400000       //图片缓冲区大小,这里设为20MB
    Bitmap::removeCache();
    Bitmap::setCache((uint16_t*)(SDRAM_START_ADDR+frame_size*3),BITMAP_CACHE_SIZE,1);//设置资源缓冲区的地址和大小,最后一个默认的0不用传,让其自动计算
    Bitmap::cacheAll();//开始缓存所有的图片

}

2、​​Screen1View.hpp​​

#ifndef SCREEN1VIEW_HPP
#define SCREEN1VIEW_HPP

#include <gui_generated/screen1_screen/Screen1ViewBase.hpp>
#include <gui/screen1_screen/Screen1Presenter.hpp>
#include <touchgfx/widgets/SnapshotWidget.hpp>


class Screen1View : public Screen1ViewBase
{
public:
    Screen1View();
    virtual ~Screen1View() {}
    virtual void setupScreen();
    virtual void tearDownScreen();

    virtual void btn_snapshot_handler();

    void handleTickEvent();
protected:

    Bitmap bitmapId;

    SnapshotWidget snapshotWidget;


};

#endif // SCREEN1VIEW_HPP

3、​​Screen1View.cpp​​

上源码

#include <gui/screen1_screen/Screen1View.hpp>
#include <touchgfx/Unicode.hpp>

Screen1View::Screen1View():
    bitmapId(BITMAP_INVALID)
{

}

void Screen1View::setupScreen()
{
    Screen1ViewBase::setupScreen();

    snapshotWidget.setPosition(this->imgBG.getX(), this->imgBG.getY(), this->imgBG.getWidth(), this->imgBG.getHeight());
}

void Screen1View::tearDownScreen()
{
    Screen1ViewBase::tearDownScreen();
}


void Screen1View::handleTickEvent()
{
    static uint16_t tickCnt = 0;
    static uint16_t val = 0;

    tickCnt++;
    if (tickCnt >= 5)
    {
        tickCnt = 0;
        val++;

        Unicode::snprintf(this->textArea1Buffer, this->TEXTAREA1_SIZE, "%d", val);
        this->textArea1.resizeToCurrentText();
        this->textArea1.invalidate();
    }


}



void Screen1View::btn_snapshot_handler()
{
   // uint8_t *frameBuffer;
    if (this->bitmapId != BITMAP_INVALID)
    {
        Bitmap::dynamicBitmapDelete(this->bitmapId);
        this->bitmapId = BITMAP_INVALID;
    }
    this->bitmapId = Bitmap::dynamicBitmapCreate(this->imgBG.getWidth(), this->imgBG.getHeight(), Bitmap::RGB888);

    if (this->bitmapId != BITMAP_INVALID)
    {
        snapshotWidget.makeSnapshot(this->bitmapId);
        this->image1.setBitmap(this->bitmapId);
        this->image1.invalidate();
        this->box1.invalidate();

    }
    else
    {

    }
   // frameBuffer = (uint8_t *)Bitmap::dynamicBitmapGetAddress(this->bitmapId);

}