android-canvas

I have a custom view in which i am drawing one big circle and a small circle on the edge of this big circle. I would like to move the small circle and so would like to have a ontouch listener only for the small circle. Could some please tell me how to set the ontouch listener for only the small circle. public class ThermoView extends View{ private ImageView mThermostatBgrd; private ImageView mCurTempArrow; private ImageView mSetPointIndicator; public static final int THEMROSTAT_BACKGROUND = 0; public static final int THEMROSTAT_CURR_TEMP = 1; public static final int THEMROSTAT_SET_POINT = 2;

I am new to android development, I am exploring about View . I come across to known two methods onDraw(Canvas c) and draw(Canvas c) . Could please explain me the difference and usage of these two methods? Which method will give better performance(FPS) when updating canvas with images? There is difference between them The onDraw(Canvas c) is a override method and automatically called when the view is being rendered. Here you can do your additional drawing like make circles, lines or whatever you want. The draw(Canvas c) is used to manually render this view (and all of its children) to the given

I am writing an pixel art app that paints images the user draws on the screen to pixel look. There are two ways to approach it. Either pixelate the image after saving or have a grid before hand so the user draws the pixel image. I don't find anything on the later method. So my issue with the first is drawing a grid where if a cell is touched I would change the color of it. I tried drawing rectangles on a canvas but that was pointless because i couldn't control the cells. I was thinking about nested for loops that creates a bitmap at each cell? The following is just a simple, illustrative

Im new to android development, and I'm finding it hard to find good examples on the camera2 api. Im working my way slowly through most issues, but on this one I am stuck. In the default camera, when you touch the screen to focus, it shows a rectangle of the focus area for a moment. I want to do something similar (Or in this case, the exact same thing to start off with so i can figure it out). I read somewhere (I think the TextureView page in the SDK docs) that you cant draw on a textureview while its being used as a camera preview - and calling the lock method will return null rather than a

I have a custom view that extends SurfaceView. I am drawing an image on the canvas. When the user touches a point on the canvas, i want to show a magnified view of the area around the touched co-ordinates. And preferably, as the finger moves around, i would like to update the magnified view's content accordingly. I was wondering if the android platform supports such a functionality natively. If not, can one of you point me to a good example that can get me started or share ideas on how to implement it. I don't do much 2D or 3D graphics of this sort and am still trying to understand the Canvas

Can I draw with anti-aliasing on canvas? I need my circles and line have smooth edges. Drawing operations want Paint . In this Paint you set Paint.setFlags(Paint.ANTI_ALIAS_FLAG) Check this out. It fairly uses smooth edges.. http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/graphics/FingerPaint.html The paint properties needed to get anti-aliasing is : mPaint = new Paint(); mPaint.setAntiAlias(true); For drawing use: mPath = new Path(); mPath.reset(); mPath.moveTo(x, y);//can be used where to trigger the path onDraw method should contain: canvas.drawPath

I'm implementing a zoomable View from examples I've found on Stack and other websites. I do want to add a drawing feature to the view. I'm able to get the paths to show up but the scaling is way off from the image behind it. I used an example android image where I traced along the shape and the paths appeared to the left and above it. Also, zooming causes it to shift (pictures below). I've been playing around with the onDraw method where the canvas is drawn but with little success. I basically use a switch whether the onTouch responds to shifting/zooming or drawing the paths. protected void