Hi falks, this is my first post, I'm a newbie in android developement and it's giving me terrible headaches.
I have to develop an app for a client that need something like a map of a floor building, this map should contain interactive graphic references such buttons rappresenting beds (it's an hospital) that should be created programmatically. I've thought the best way to do it is to create a big background image of the floor map, and adding on top the beds buttons. The map image is very big so it should scroll on touch, for that I've found a great example here: http://www.anddev.org/large_image_scrolling_using_low_level_touch_events-t11182.html what I'd like to do now is to create an array of buttons overlaying the map, but eclipse give an error if I try to create an instance of a button inside the SampleView ( extends RelativeLayout) constructor. Why? is this illegal? and how can I create this array of buttons? maybe I have to create outside in the main activity class, but then I don't know how to translate them following the map image. following the code thanks in advance [code]package com.works.Unitel; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Rect; import android.os.Bundle; import android.view.Display; import android.view.MotionEvent; import android.view.WindowManager; import android.widget.Button; import android.widget.RelativeLayout; public class UnitelActivity extends Activity { /** Called when the activity is first created. */ private static int displayWidth = 0; private static int displayHeight = 0; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Display display = ((WindowManager) getSystemService(Context.WINDOW_SERVICE)) .getDefaultDisplay(); displayWidth = display.getWidth(); displayHeight = display.getHeight(); SampleView rl = new SampleView(this); setContentView(rl); rl.setBackgroundColor(Color.YELLOW); // very strange, it doesn't show the image without setting a //background } private static class SampleView extends RelativeLayout { private static Button bt; private static Bitmap bmLargeImage; // bitmap large enough to be // scrolled private static Rect displayRect = null; // rect we display to private Rect scrollRect = null; // rect we scroll over our bitmap with private int scrollRectX = 0; // current left location of scroll rect private int scrollRectY = 0; // current top location of scroll rect private float scrollByX = 0; // x amount to scroll by private float scrollByY = 0; // y amount to scroll by private float startX = 0; // track x from one ACTION_MOVE to the next private float startY = 0; // track y from one ACTION_MOVE to the next public SampleView(Context context) { super(context); bt = new Button(this); // here is where eclipse throw the error!!! :( bmLargeImage = BitmapFactory.decodeResource(getResources(), R.drawable.piano); displayRect = new Rect(0, 0, displayWidth, displayHeight); scrollRect = new Rect(0, 0, displayWidth, displayHeight); } protected void onDraw(Canvas canvas) { // Our move updates are calculated in ACTION_MOVE in the opposite // direction // from how we want to move the scroll rect. Think of this as // dragging to // the left being the same as sliding the scroll rect to the right. int newScrollRectX = scrollRectX - (int) scrollByX; int newScrollRectY = scrollRectY - (int) scrollByY; // Don't scroll off the left or right edges of the bitmap. if (newScrollRectX < 0) newScrollRectX = 0; else if (newScrollRectX > (bmLargeImage.getWidth() - displayWidth)) newScrollRectX = (bmLargeImage.getWidth() - displayWidth); // Don't scroll off the top or bottom edges of the bitmap. if (newScrollRectY < 0) newScrollRectY = 0; else if (newScrollRectY > (bmLargeImage.getHeight() - displayHeight)) newScrollRectY = (bmLargeImage.getHeight() - displayHeight); // We have our updated scroll rect coordinates, set them and draw. scrollRect.set(newScrollRectX, newScrollRectY, newScrollRectX + displayWidth, newScrollRectY + displayHeight); Paint paint = new Paint(); canvas.drawBitmap(bmLargeImage, scrollRect, displayRect, paint); // Reset current scroll coordinates to reflect the latest updates, // so we can repeat this update process. scrollRectX = newScrollRectX; scrollRectY = newScrollRectY; } @Override public boolean onTouchEvent(MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_DOWN: // Remember our initial down event location. startX = event.getRawX(); startY = event.getRawY(); break; case MotionEvent.ACTION_MOVE: float x = event.getRawX(); float y = event.getRawY(); // Calculate move update. This will happen many times // during the course of a single movement gesture. scrollByX = x - startX; // move update x increment scrollByY = y - startY; // move update y increment startX = x; // reset initial values to latest startY = y; invalidate(); // force a redraw break; } return true; // done with this event so consume it } } } [/code] -- You received this message because you are subscribed to the Google Groups "Android Developers" 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-developers?hl=en
