i'm pretty much a new in android development. I try to draw line based on touch event. It work well with out scrollview. But, when I use scrollView, it just doesn't work. I read some question and answer in other thread, but nothing can get me understand how should the code.
here is my code:
public class CustomDrawingView extends View
{
private final int paintColor = Color.BLACK;
private Paint drawPaint;
private Path path = new Path();
private boolean clearCanvas = false;
public CustomDrawingView(Context context, AttributeSet attrs)
{
super (context, attrs);
setupPaint();
}
private void setupPaint() {
drawPaint = new Paint();
drawPaint.setColor(paintColor);
drawPaint.setAntiAlias(true);
drawPaint.setStrokeWidth(5);
drawPaint.setStyle(Paint.Style.STROKE);
drawPaint.setStrokeJoin(Paint.Join.ROUND);
drawPaint.setStrokeCap(Paint.Cap.ROUND);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float touchX = event.getX();
float touchY = event.getY();
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
path.moveTo(touchX, touchY);
break;
case MotionEvent.ACTION_MOVE:
path.lineTo(touchX, touchY);
break;
}
postInvalidate();
return true;
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawPath(path, drawPaint);
}
public void clearScreen()
{
path.reset();
postInvalidate();
}
}
MainActifity:
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.mirana.touchinteraction.MainActivity">
<ScrollView
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<com.example.mirana.touchinteraction.CustomDrawingView
android:id="@+id/simpleDrawingView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</ScrollView>
</RelativeLayout>
how to able to draw line in the screen based on the touch Interaction? Please help me.
on the image below, the screen contain "work draw" is what I want my code run (remove scrollView from xml). The blank screen is the result when I add scrollview to the xml just like in the code above. I can draw anything by touch and drag my pointer to the screen.
