I may be wrong but It is probably being called multiple times by the Android system in setting up your UI. At work I do a lot of programming with Qt and they document that certain methods will be called multiple times when setting up the UI.
Thanks, Justin ---------------------------------------------------------------------- There are only 10 types of people in the world... Those who know binary and those who don't. ---------------------------------------------------------------------- On Mon, Dec 7, 2009 at 9:31 AM, DanaH <[email protected]> wrote: > Here is a short program where my intent is to scale up or down the > size of a circle when the zoom controls are used. In addition to my > intended behavior, I am getting two "extra" (unintended) calls to the > onDraw() function in response to my zoomControl onClick callback. (I > have used DDMS to log my debug statements.) > > Can anyone explain the source of the onDraw() calls besides the > zoomControl onClick() method? > > > --------------------------------------------------------------------------------------- > package com.example.simpledraw; > > import android.app.Activity; > import android.content.Context; > import android.graphics.Canvas; > import android.graphics.Color; > import android.graphics.Paint; > import android.graphics.Path; > import android.graphics.Path.Direction; > import android.os.Bundle; > import android.util.Log; > import android.view.View; > import android.view.View.OnClickListener; > import android.widget.RelativeLayout; > import android.widget.ZoomControls; > > public class SimpleDraw extends Activity { > > private static final String TAG = "SimpleDrawActivity"; > public static double scale; > > /** Called when the activity is first created. */ > @Override > public void onCreate(Bundle savedInstanceState) { > super.onCreate(savedInstanceState); > > scale = 2.0; > RelativeLayout relativeLayout = new RelativeLayout > (this); > setContentView(relativeLayout); > final MyView myView = new MyView(this); > RelativeLayout.LayoutParams myViewLayoutParams = > new RelativeLayout.LayoutParams > (RelativeLayout.LayoutParams.FILL_PARENT,RelativeLayout.LayoutParams.FILL_PARENT > ); > relativeLayout.addView(myView, myViewLayoutParams); > RelativeLayout.LayoutParams zoomControlsLayoutParams = > new RelativeLayout.LayoutParams > (RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT > ); > zoomControlsLayoutParams.addRule > (RelativeLayout.ALIGN_PARENT_BOTTOM); > zoomControlsLayoutParams.addRule > (RelativeLayout.CENTER_HORIZONTAL); > ZoomControls zoomControls = new ZoomControls(this); > > relativeLayout.addView > (zoomControls,zoomControlsLayoutParams); > myView.setEnabled(true); > zoomControls.setIsZoomInEnabled(true); > zoomControls.setIsZoomOutEnabled(true); > zoomControls.setOnZoomInClickListener(new OnClickListener() > { > public void onClick(View v) { > myView.invalidate(); > scale *= 1.25; > Log.v(TAG, "The scale is " + scale); > } > }); > zoomControls.setOnZoomOutClickListener(new OnClickListener() > { > public void onClick(View v) { > myView.invalidate(); > scale *= 0.8; > Log.v(TAG, "The scale is " + scale); > } > }); > } > > static public class MyView extends View { > > Integer number = 0; > > public MyView(Context context) { > super(context); > } > @Override > protected void onDraw(Canvas canvas){ > //super.onDraw(canvas); > Log.w(TAG, "The onDraw() method is called for the " + number > + " > time."); > //Log.w(TAG, "The view calling OnDraw is " + this.getId() ); > canvas.drawColor(0); > Path circle = new Path(); > circle.addCircle(150, 150, (int)(scale*10.), Direction.CW); > Paint cPaint = new Paint(); > cPaint.setColor(Color.LTGRAY); > canvas.drawPath(circle, cPaint); > Paint textPaint = new Paint(); > textPaint.setColor(Color.GREEN); > canvas.drawText(number.toString(), 150, 250, textPaint); > number++; > > } > } > > > } > > -- > You received this message because you are subscribed to the Google > Groups "Android Beginners" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected]<android-beginners%[email protected]> > For more options, visit this group at > http://groups.google.com/group/android-beginners?hl=en -- You received this message because you are subscribed to the Google Groups "Android Beginners" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en
