I had a question regarding Android programming. I have created an application to take in data via Bluetooth and I would like to use that input as sort of a "game controller" to move an image around a screen. For instance, if the "up" command was given, the image (or even a colored circle) would move a few pixels up.
Can someone point me in the right direction? I thought of using a canvas and redrawing the image every so often but I don't know how to do this and I thought there might be a better/simpler way. I don't need anything fancy.
What i would do. Catch the up command, then have a class lets call it Circle which will hold the current circles position, size etc.
Whenever you catch the up command or left or right or any kind of command, you would redraw the image in that position. I would also use a custom surface view for the drawing and an Activity for catching all the inputs and passing them onto the object.
I would check out
http://www.javacodegeeks.com/2011/07/android-game-development-moving-images.html
and read through the whole series, if you have the time. It is quite a good read.
Related
im new to this android things. And i have to develop an application that can help an autism to learn numbers. I have a few ideas and I've been trying to learn and implement the code. But it's failed. The question is how can i apply the motion code or sprite to draw a numbers or letter? For example like this, i wanna make the penguin move through the line and draw a number nine.
There is example from mybringback.com which is the image move to draw a rectangle. How can i implement it to draw a number? Im sorry if i asking too much, i just trying to get some ideas.
I think that you should first build an utility program, in order to create the "path vector".
What I mean by path vector is simply a vector of Points (where a point has x value, and y value). And your utility should let you draw whatever you want, with a simple pen. You should draw on surface and store points when mouse is down, and ignore points when mouse is up.
Then, in the main program, you will just have to read at the path of your number/letter.
I've tried to implement something like this for the Sugar OLPC platform, without serializing path into files : I was able to draw, and to view the animation. And I used the process I've just described you.
Hope it can help you.
P.S : I used the word mouse, but you guessed that I talk about finger ...
There are various ways to achieve animation effects. One approach that is quite versatile involves creating a custom View or SurfaceView in which you Override the onDraw method. Various tutorials can be found on this; the official Android discussion of it is here:
http://developer.android.com/guide/topics/graphics/2d-graphics.html#on-view
Your implementation will look something like this:
// Find elapsed time since previous draw
// Compute new position of drawable/bitmap along figure
// Draw bitmap in appropriate location
// Add line to buffer containing segments of curve drawn so far
// Render all segments in curve buffer
// Take some action to call for the rendering of the next frame (this may be done in another thread)
Obviously a simplification. For a very simplistic tutorial, see here:
http://www.techrepublic.com/blog/software-engineer/bouncing-a-ball-on-androids-canvas/1733/
Note that different implementations of this technique will require different levels of involvement by you; for example, if you use a SurfaceView, you are in charge of calling the onDraw method, whereas subclassing the normal View lets you leave Android in charge of redrawing (at the expense of limiting your ability to draw on a different thread). In this respect, Google remains your friend =]
I am looking for a way to do something similar to the image at the bottom. However, I need the selection area to go all the way across and be able to be moved up and down the image via touch. I just need to get the coordinates of the selected pixels.
I am assuming I will need to create a canvas and draw the image background, but after that I'm pretty lost. If anyone can provide an example of something like this, or just a basic walkthrough on what to read up on I would really appreciate it.
In the project I am working on I decided to use SurfaceView instead of a custom double buffered medium. It provides everything I need and it's already double buffered.
The problem is that it wont let me specify multiple dirty rectangles to redraw.
SurfaceView.lockCanvas(Rect) only allows single rectangle and without parameter it's pretty expensive to redraw whole thing. Another solution to call lockCanvas(Rect) for each Rect causes eye-bleeding blinking in the screen, obviously.
Do you have any solution giving the opportunity staying inside Android API field, if not do you have any external alternatives I can use?
If you know the dirty areas before you need to call lockCanvas (sounds like you might), you could calculate a "super rectangle" that locks an area that contains all of your rectangle. For example if your rectangles are (using l,r,t,b coordinates) [0,10,0,20] and [15,30,10,35], your super rectangle would be [0,30,0,35].
Suppose I am writing a word "abc" in my GestureOverlayView and while doing so I need to save all those alphabets in the screen until I press a clear button.Can anyone tell me a good way to do this..
I will write "a" which is taken as a gesture (not as stroke) i.e One thing I though of was like use a ImageView or SurfaceView on bottom of a GestureOverLayView.and Suppose when I draw "a" on GestureOverLayView then in the "onGesturePerformed" event it will take the Gesture and then get the strokes and then convert them into paths and then draw the paths onto the underlying ImageView or SurfaceView.Can anyone suggest me the code or guide me.I tried various combinations of them but couldn't solve it..
There's an app called GestureBuilder in the samples directory of the SDK. This app shows how to persist gestures drawn by the user.
I realize this is an old question, but you can "cheat" by increasing the fadeOffset to some ridiculously high number. This can be done either in the xml
android:fadeOffset = "some very large number"
whatever, or programatically,
yourgestureoverlayView.SetFadeOffset(some very large number in milliseconds)
I'm fairly new to the Android platform and was wondering if I could get some advice for my current head scratcher:
I'm making an app which in one view will need an image, which can be scrolled on one axis, with a load of selectable points over the top of it. Each point needs to be positionable on the x and y (unlikely to change once the app is running, but I'll need to fine tune the positions whilst I'm developing it).
I'd like to be able to let the user select each point and have a graphic drawn on the point the user has selected or just draw a graphic on one/more points without user intervention.
I though for the selectable points I could extend the checkbox with a custom image for the selected state - does that sounds right, or is there a better way of doing this? Is there any thing I can read up on doing this, I can't seem to find anything on the net about replacing the default images?
I was going to use the absolute layout, but see that it's been depreciated and I can't find anything to replace it.
Can anyone give me some code or advice on where to read up on what I need to do?
Thank you in advance
This really feels like something you should be doing with the Canvas and 2D graphics, rather than trying to twist the widget framework to fit.