want to draw over a changing solid-color background

by Rob Y. » Fri, 23 Apr 2010 10:56:32 GMT

Sponsored Links
 I'm trying to draw an animated picture over a background that I want
to shift gradually in color.

The picture is kept in a bitmap, and on each frame, I erase the
background to the new background color and then draw the bitmap on top
of it.  The bitmap was originally cleared to Color.TRANSPARENT, and
that works.  I can see the background color.  But as I animate my
image, each pixel in the bitmap that I 'erase' to Color.TRANSPARENT
seems to remain whatever color it originally was.  Eventually I just
end up with a big blob of color where the moving image should be.

Am I doing something wrong?  How come Color.TRANSPARENT results in
transparency when I use it to drawColor to my bitmap canvas, but not
when I draw with a Color.TRANSPARENT paint to the same canvas?


Other Threads

1. LG Optimus and the Rise of the Cheap Androids!


Evidently it's with devices like these that Google wants to take over India:


What i find quite unusual is that Indian scripts (
http://bit.ly/wpIndicScripts) that are supported in Unicode are not rendered
at all in the Android 2.1 that i have on my Samsung Galaxy S.  All i see is
a rectangular blob.  Has that been rectified in Android 2.2?




2. Listen/bind a hardwarebutton to a activity/event

Hey there, this is kind of a wide question that I'll break down for
you. In general I'm wondering if its is possible, if so then how, to
bind/listen to a hardware-button to my application.

    * Is it possible to make a hardware-button start my app on shot/
long press?
    * Is it possible to start/trigger my widget on a longpress of a
    * Is it possible to (when i have the app in the background) make a
hardwarebutton triger this app to the foreground/activate it?
    * Is it possible to let a servive listen to long-press of a
    * The camera activity on some phones has a camerabutton, can this
button be programed to work with my app?

What I want to do is that upon a longrpress (hold valume up/home-
button for more than 3 seconds) start/execute a activity in my
application like the camera-application and its camerabutton.

Im searching for any and all information about this right now as I
cant find any real answer ;(


3. Can not update app on the Market now

4. Android: DeadObjectException for InputMethodService (SoftKeyboard API sample)

5. How to pass a Context variable from one Activity to another ?

6. Segmented video streaming on Android

7. how to inject view from a dialog layout xml file when using RoboGuice?