Java - Making bitmaps scale to your screen size?

Question

I am creating an app and want my ui to scale with the phone. I am importing bitmaps into a canvas and drawing them as follows:

public class MainMenu extends View {

private RectF titleBounds, playBounds, scoreBounds, soundBounds, creditBounds;
private Paint titlePaint, playPaint;

private boolean playClick = false, startPlay = false, scoreClick = false, startScore = false, soundClick = false, startSound = false, creditsClick = false, startCredits = false;


public Bitmap play;
public Bitmap playGlow;

public Bitmap sound;
public Bitmap soundGlow;


public int screenWidth, screenHeight;

public MainMenu(Context context) {
    super(context);

    titleBounds = new RectF();
    playBounds = new RectF();
    scoreBounds = new RectF();
    soundBounds = new RectF();
    creditBounds = new RectF();

    titlePaint = new Paint();
    playPaint = new Paint();

    play = BitmapFactory.decodeResource(getResources(), R.drawable.play);
    playGlow = BitmapFactory.decodeResource(getResources(), R.drawable.playglow);

    sound = BitmapFactory.decodeResource(getResources(), R.drawable.sound);
    soundGlow = BitmapFactory.decodeResource(getResources(), R.drawable.soundglow);


    // Get window size and save it to screenWidth and screenHeight.
    WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
    Display display = wm.getDefaultDisplay();
    Point size = new Point();
    display.getSize(size); 
    screenWidth = size.x;
    screenHeight = size.y;
}


@Override protected void onDraw(Canvas canvas) {


    ViewGroup parent = (ViewGroup)getParent();

    playBounds.set(screenWidth / 2 - play.getWidth() / 2, screenHeight * 1/3 - play.getHeight() / 2, playBounds.left + play.getWidth(), playBounds.top + play.getHeight());
    soundBounds.set(scoreBounds.centerX() - sound.getWidth() / 2, scoreBounds.bottom + 10, soundBounds.left + sound.getWidth(), soundBounds.top + sound.getHeight());

The problem is theres nothing to scale the image to fit the phone, it just reads the x and y size of the image I import. What method is there for scaling images?

Rod_Algonquin · Answer 1 · 2014-06-12T01:50:44.417

0

Use the createScaledBitmap of the Bitmap class

bitmap = Bitmap.createScaledBitmap(bitmap, scaledWidth, scaledHeight, true);

It will scale your bitmap but not greater than the width and height that is because it can cause blurriness to your bitmap.

documentation:

    Creates a new bitmap, scaled from an existing bitmap, when possible. 
   If the specified width and height are the same as the current width and height of the source bitmap,
   the source bitmap is returned and no new bitmap is created.

for full screen

bitmap  = Bitmap.createScaledBitmap(bitmap, screenWidth , screenHeight , true);

edited Jun 12 '14 at 01:50

answered Jun 11 '14 at 21:10

Rod_Algonquin

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So then what is my scaledHeight and scaledWidth – Divergent Jun 11 '14 at 21:11
@Divergent the height and width you want your bitmap to be. – Rod_Algonquin Jun 11 '14 at 21:13
Or I just put the size I want it to be and it will automatically resize to other phones? – Divergent Jun 11 '14 at 21:16
@Divergent as long the width and height of your resize method is not greater than the image see documention if it is not greater than the image and then it is fine. – Rod_Algonquin Jun 11 '14 at 21:16
Im having troubles with this :C Would you be so kind as to team view me? – Divergent Jun 12 '14 at 01:25
@Divergent may I know when are you using this view.. because you can easily do this with ImageView. – Rod_Algonquin Jun 12 '14 at 01:37
Im drawing bitmaps to canvas – Divergent Jun 12 '14 at 01:42
I understand that much, but for some reason its not scaling my image to the size I want. Does it only scale up? Because the images Im using are very large. – Divergent Jun 12 '14 at 01:57
@Divergent size.x and size.y will return in pixel you need to convert it to DP so it is compatible with the screen. – Rod_Algonquin Jun 12 '14 at 02:02
Im doing what its saying to do and its not working at all could you take a look over teamview or something please? :C as I said im still new to java so I am probably missing something – Divergent Jun 12 '14 at 13:33

Java - Making bitmaps scale to your screen size?

1 Answers1