add touchtest examples

apps/samples/touchtest.cc

@@ -0,0 +1,51 @@
+#include <cdroid.h>
+class TouchWindow:public Window{
+private:
+    Point mTouchPoint;
+    int mGridSize;
+    bool mClear;
+public:
+    TouchWindow(int w,int h):Window(0,0,w,h){
+	 mGridSize =10;
+    }
+    bool onTouchEvent(MotionEvent&event)override{
+        mTouchPoint.x = event.getX();
+	mTouchPoint.y = event.getY();
+	mClear = event.getActionMasked()==MotionEvent::ACTION_UP;
+	LOGI("Point(%d,%d)",mTouchPoint.x,mTouchPoint.y);
+	invalidate();
+	return true;
+    }
+    void onDraw(Canvas&canvas){
+	if(mClear){
+	    canvas.set_source_rgb(0,0,0);
+	    canvas.rectangle(0,0,getWidth(),getHeight());
+	    canvas.fill();
+	}
+        for(int x=0,i=0;x<getWidth();x+=mGridSize,i++){
+	    canvas.move_to(x,0);
+	    canvas.line_to(x,getHeight());
+	    canvas.set_source_rgba(.5,.5,.5,(i%10==0)?1.f:0.4f);
+	    canvas.stroke();
+	}
+	for(int y=0,i=0;y<getHeight();y+=mGridSize,i++){
+	    canvas.move_to(0,y);
+	    canvas.line_to(getWidth(),y);
+	    canvas.set_source_rgba(.5,.5,.5,(i%10==0)?1.f:0.4f);
+	    canvas.stroke();
+	}
+	canvas.stroke();
+	canvas.set_source_rgb(0,1,0);
+	canvas.arc(mTouchPoint.x,mTouchPoint.y,6,0,M_PI*2.f);
+	canvas.fill();
+    }
+};
+int main(int argc,const char*argv[]){
+    App app(argc,argv);
+    Point sz;
+    WindowManager::getInstance().getDefaultDisplay().getRealSize(sz);
+    LOGI("DisplaySize=%dx%d",sz.x,sz.y);
+    Window*w=new TouchWindow(-1,-1);
+    w->invalidate();
+    return app.exec();
+}