Android :: How To Obtain The Current Bitmap Of A Canvas
Nov 16, 2010
I want to get the current bitmap associated with my canvas so I can perform operations on it. I can't see how to do this though.
I've seen some examples where you create a bitmap and set the canvas to use this bitmap, so obviously you can then access it later, but I'm using the canvas returned from a SurfaceHolder so there's no constructor.
For instance, examples often show this kind of thing:
So at this point I can see bmp.
In my case, the canvas is obtained by:
So how can I get the bitmap for c?
In short, my aim is to capture the current canvas contents where I have drawn "stuff", and make a copy of it, reversed, to put underneath. Like a reflection. The example of this that I found performed it all via bitmaps, so I assumed I needed to somehow capture the current canvas to a bitmap to then use it.
My loadMap() method generate a canvas.throwIfRecycled exception when i try to load a new map. When i start the game, the initial map loads and work fine though, its only when i try to load a new map that i get the exception ..
How can i "reset" canvas and the bitmap i use to draw into, so i can startover fresh with them ? here's what i use to create and draw my maps:
So basicaly once i created and used picDest and canvas, i cannot figure how to reset it all for when i want to load a new map..
I need to capture an image from camera and display on surfaceview for my project. I am trying to obtain bitmap from data in onPreviewFrame method of previewCallback and display on surface using canvas.
I am getting the following logs when i am changing the wallpaper for Homescreen. Even i am recycling the bitmap is done when the wallpaper changes in OnWallpaperChanged(). Still i m getting the bellow error.
I am starting to develop a game. Right now I got a sprite animation going when a player moves across using sprite sheet. In my sprite sheet the character is always facing the same way, left. Now if I want the character to move right, I want it to be facing right. So is there a quick way in android to invert the bitmap after it has been loaded in? Or do I have to create sprite sheet for character facing right?
I want to draw a bitmap on a canvas with bigger size than it is. I can use canvas.drawBitmap(bitmap, null, destRect, null); but that gives a poor quality, as the result is pixelated, if the source image is sightly smaller than the destination rectangle. How can i draw my bitmap using bilinear or bicubic resampling?
At canvas there are many methods (canvas.rotate (35); canvas.drawBitmap (myBitmap, x, y, null); and many other things), but the method of mirror reflexion of image is absent (or I have not found it). At Bitmap too not that is not. Is it possible to reflect horizontally on canvas the image given Bitmap?
Is there way to dump the current screen to a bitmap in Android?
And what about dump screen of other applications? For example, running a service background, the foreground app could send an intent to start the service, and capture the current screen and save as a bitmap.
I am about to build an app in Android that will act as a clock in card for employees on the road.
At teh start of a job the user will click a button that will record the GPS location and current time (thus verifying that he is where he should be at a given time) and again at the end of teh job he records the time and GPS location.
SO I reckon this will be easy enough, except that I cant find a way of pulling current location data, the nearest I can find is "onLocationChanged" which implies that I cannot get a stationary GPS read. I know it has to be possible to do this but cannot find a working example of how it would be achieved.
As we know, we can rotate a bitmap through 2 ways. The 1st way is: Matrix mt = new Matrix(); mt. postRotate (degree);Bitmap bitmap = CreateBitmap(src, 0, 0, w, h, mt, true); canvs.drawBitmap(bitmap, 0, 0, paint); In this way, we always need create new bitmap for every rotation, it is not good way for high performance game or app.The 2nd way is: canvas.save(); canvas.rotate(degree); canvas.drawBitmap(bitmap, 0, 0, paint); canvas.restore();In this way, we avoid creating new bitmap frequently, but the rotation bitmap is distortion, the bitmap quality is worse than first way.So, Is there 3rd way to rotate bitmap with high performance and good quality? Your any comments are really appreciated!
I have a very large image and I only want to display a section the size of the display (no scaling), and the section should just be the center of the image. Because the image is very large I cannot read the entire image into memory and then crop it. This is what I have so far but it will give OutOfMemory for large images. Also I don't think inSampleSize applies because I want to crop the image, not lower the resolution.
Uri data = getIntent().getData(); Input Stream is = getContentResolver().openInputStream(data); Bitmap bitmap = BitmapFactory.decodeStream(is, null, null);
I am 1) taking a picture and 2) then draw another Bitmap on top of it 3) then I store it
I am doing it as follows and it works on the emulator.
On the device I get a OutOfMemoryError: bitmap size exceeds VM budget android.graphics.Bitmap.nativeCopy(Native Method) android.graphics.Bitmap.copy(Bitmap.java:199) in the line copy the Bitmap to get a mutable Bitmap.
What I am asking:
a) Is there a better way to do what I am doing? 1) take a picture 2) draw another Bitmap on top of it 3) then I store it
b) What is the best way to create a mutable Bitmap from the picture I just took with the camera?
In my app, resolution is not an issue. If it works better for small photos that would be fine.
My goal is the draw a bitmap onto another bitmap but rotated 90 degress. whats the most efficient way to do that. My current method is as follows which is horribly bad because it creates a new bitmap every time.
The default behavior of an activity when BACK softkey is pressed is, GO BACK TO PREVIOUS ACTIVITY. If some the same activity is waiting for some response from server or some data updation is going on and then press BACK, I want to wait on the same screen till the current task is completely processed and then move out to the previous activity.
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I want to draw a shape(many circles particularly) into a Specific Bitmap. I have never used canvas / 2D graphs etc. As i see it i create a Drawable put the bitmap in it then "canvas-it" to the shapes i want etc.
I would like to write an app on Android to upload my GPS location to an external website once every 5 minutes. This needs to have as minimal an impact on battery life as possible, but it also needs to work without any user interaction. (Background: I'm competing in an Ironman triathlon which will take me about 14 hours to complete, and want to broadcast my location in near-real-time but without having to worry about fiddling with my phone.) So my initial thought is to write a Service which uses LocationManager.requestLocationUpdates() with a minTime of 5 minutes, but will this actually wake the device up every 5 minutes for my service to do its job?
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The documentation of ServiceState can be found here: http://developer.android.com/reference/android/telephony/ServiceState.html
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