2. Draw a red block in c++

#define LOG_NDEBUG 0
#define LOG_TAG "NativeUITest"
#include <utils/Log.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
 
#include <utils/IPCThreadState.h>
#include <utils/ProcessState.h>
#include <ui/SurfaceComposerClient.h>
#include <ui/Surface.h>
#include <ui/ISurfaceComposer.h>
#include "SkCanvas.h"
#include "SkDevice.h"
 
using namespace android;
 
static inline SkBitmap::Config convertPixelFormat(PixelFormat format)
{
    /* note: if PIXEL_FORMAT_XRGB_8888 means that all alpha bytes are 0xFF, 
        then we can map to SkBitmap::kARGB_8888_Config, and optionally call
        bitmap.setIsOpaque(true) on the resulting SkBitmap (as an accelerator)
    */
    switch (format) {
        case PIXEL_FORMAT_RGBA_8888:    return SkBitmap::kARGB_8888_Config;
        case PIXEL_FORMAT_RGBA_4444:    return SkBitmap::kARGB_4444_Config;
        case PIXEL_FORMAT_RGB_565:      return SkBitmap::kRGB_565_Config;
        case PIXEL_FORMAT_A_8:          return SkBitmap::kA8_Config;
        default:                        return SkBitmap::kNo_Config;
    }
}
 
int main(int argc, char** argv)
{
    sp<ProcessState> proc = ProcessState::self();
    proc->startThreadPool();
    int pid = getpid();
    int nState = 0;
    sp<SurfaceComposerClient> client = new SurfaceComposerClient;
    sp<Surface> surface(client->createSurface(pid, 0, 176, 144, PIXEL_FORMAT_OPAQUE, ISurfaceComposer::eFXSurfaceNormal));

    //set surface layer to INT_MAX
    client->openTransaction();
    //nState = surface->setSize(176, 144);
    nState = surface->setPosition(100, 200);
    nState = surface->setLayer(INT_MAX);
    nState = surface->show();
    client->closeTransaction();

    //Start painting...
    client->openTransaction();
    Rect rect(0,0,176,144);
    Region dirtyRegion(rect);
    Surface::SurfaceInfo info;
    status_t err = surface->lock(&info, &dirtyRegion);
    if(err < 0)
    {
        client->closeTransaction();
        IPCThreadState::self()->stopProcess();
        return -1;
    }
    SkCanvas myCanvas;
    SkCanvas* canvas = &myCanvas;
    SkBitmap bitmap;
    bitmap.setConfig(convertPixelFormat(info.format), info.w, info.h, info.bpr);
    bitmap.setPixels(info.bits);
    canvas->setBitmapDevice(bitmap);
    canvas->clipRegion(dirtyRegion.toSkRegion());
    int saveCount = canvas->save();
    //paint hole
    //canvas->drawColor(0, SkPorterDuff::kClear_Mode);
    //paint a red block
    canvas->drawARGB(255, 255, 0, 0);
    canvas->restoreToCount(saveCount);
    canvas->setBitmapDevice(SkBitmap());
    nState = surface->unlockAndPost();
    LOGI("surface->unlockAndPost, %d", nState);
    client->closeTransaction();
 
    sleep(10);
    IPCThreadState::self()->stopProcess();
    LOGI("quiting...");
    return 0;
}