How can I center this rectangle and image in the y axis? - java

So far, my image starts at 0,0 and scales properly. There is a black bar under it. How can I align it so that it is centered along the y, with a black bar above and below the image?
edit: also, what are "this.getWidth(), this.getHeight()" referring to when I make the object "dest" - the width of mBitmap? The documentation does say they represent the width of the view, I just want to make sure I'm correct in thinking that is it mBitmap.
public class SpotGameActivity extends Activity {
private Bitmap mBitmap;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.dpi2b);
setContentView(new BitMapView(this, mBitmap));
}
class BitMapView extends View {
Bitmap mBitmap = null;
public BitMapView(Context context, Bitmap bm) {
super(context);
mBitmap = bm;
}
#Override
protected void onDraw(Canvas canvas) {
//DisplayMetrics metrics = new DisplayMetrics();
//getWindowManager().getDefaultDisplay().getMetrics(metrics);
// called when view is drawn
Paint paint = new Paint();
paint.setFilterBitmap(true);
// The image will be scaled so it will fill the width, and the
// height will preserve the image’s aspect ration
float aspectRatio = ((float) mBitmap.getWidth()) / mBitmap.getHeight();
Rect dest = new Rect(0, 0, this.getWidth(),(int) (this.getWidth() / aspectRatio));
String AR = Double.toString(aspectRatio);
canvas.drawBitmap(mBitmap, null, dest, paint);
Toast.makeText(SpotGameActivity.this, AR, Toast.LENGTH_SHORT).show();
}
I've now gotten the difference between the view size and image size. I've divided the difference by 2 but now, my image is align to the bottom of the screen rather than the middle of the y-axis. any tips?:
#Override
protected void onDraw(Canvas canvas) {
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int scrHeight = this.getHeight();
String sH = Integer.toString(scrHeight);
Log.v(TAG, "scrHeight =" + sH );
int imgHeight= mBitmap.getHeight();
String iH = Integer.toString(imgHeight);
Log.v(TAG, "imgHeight =" + iH );
int diff = scrHeight - imgHeight;
String dif = Integer.toString(diff);
Log.v(TAG, "diff =" + dif );
int dvd= diff/2;
// called when view is drawn
Paint paint = new Paint();
paint.setFilterBitmap(true);
// The image will be scaled so it will fill the width, and the
// height will preserve the image’s aspect ration
float aspectRatio = ((float) mBitmap.getWidth()) / mBitmap.getHeight();
Rect dest = new Rect(0, dvd, this.getWidth(),(int) (this.getWidth() / aspectRatio)+dvd);
String AR = Double.toString(dvd);
canvas.drawBitmap(mBitmap, null, dest, paint);
Toast.makeText(SpotGameActivity.this, AR, Toast.LENGTH_SHORT).show();

Related

Android studio - Center non-transparent part of picture

I'm making an app that can freehand crop a picture using a canvas in android studio. My problem is that after cropping the picture, the cropped part stays in the same exact position as it was originally, whereas i want it to get centered and enlargened. Is there any way to take the non-transparent part and center it, or maybe remove the transparent part all-together?
Screenshot of my app where i want the banana to be centered
https://i.stack.imgur.com/8OKNT.png
Bitmap bitmap;
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Rect src;
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canvas.drawPath(path, paint);
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Bitmap croppedBitmap =
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How to make images on Bitmap smaller?

I am trying to build a simple game on android and while setting the background image and other image assets on my main screen it is appearing too big as shown in the below image.
The actual size of the image is 1920x1080 and I want it to fit my screen like the image shown below:
The code for I have used is:
public class PoliceView extends View {
private Bitmap police;
private Bitmap background;
private Paint scorePaint = new Paint();
private Bitmap life[] = new Bitmap[2];
public PoliceView(Context context) {
super(context);
police = BitmapFactory.decodeResource(getResources(),R.drawable.police);
background = BitmapFactory.decodeResource(getResources(),R.drawable.gamebackground);
scorePaint.setColor(Color.BLACK);
scorePaint.setTextSize(70);
scorePaint.setTypeface(Typeface.DEFAULT_BOLD);
scorePaint.setAntiAlias(true);
life[0] = BitmapFactory.decodeResource(getResources(),R.drawable.heart);
life[1] = BitmapFactory.decodeResource(getResources(),R.drawable.brokenheart);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//The order of draw matters as objects are drawn in this same order
canvas.drawBitmap(background,0,0,null);
canvas.drawBitmap(police, 0, 0, null);
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How can I resize the images to fit the screen??
i use this code for resize image
Bitmap tmp = BitmapFactory.decodeFile(mPath);
ResizeWidth = (int) (your size);
ResizeHeight = (int) (your size);
Bitmap bitmap = Bitmap.createBitmap(ResizeWidth, ResizeHeight, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
Bitmap scaled = Bitmap.createScaledBitmap(tmp, ResizeWidth, ResizeHeight, true);
int leftOffset = 0;
int topOffset = 0;
canvas.drawBitmap(scaled, leftOffset, topOffset, null);
How to resize bitmap in canvas?
canvas.save(); // Save current canvas params (not only scale)
canvas.scale(scaleX, scaleY);
canvas.restore(); // Restore current canvas params
scale = 1.0f will draw the same visible size bitmap

Java - Making bitmaps scale to your screen size?

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

Android custom view not showing

I am working on an Android version of Gomoku. I am quite new to Java in general and even more so to Android. I am following a book called "Hello Android" where the author teaches the basics through making a game of Sudoku. I am following it loosely, leaving out features not needed for my Gomoku. However, a new view is made when New Game is pressed and although the book continues on as if it should be working, what should be drawn is not showing for me at all. Here is the code that deals with the stuff:
Mainactivity.java:
private void startGame() {
Log.d(TAG, "Clicked New Game");
Intent intent = new Intent(this, Game.class);
startActivity(intent);
}
Game.java:
public class Game extends Activity {
private static final String TAG = "Game";
private int board[] = new int[10 * 10];
private GameView gameView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "Game.onCreate called");
gameView = new GameView(this);
gameView.requestFocus();
Log.d(TAG, "Game.onCreate finished");
}
}
GameView.java:
public class GameView extends View {
private static final String TAG = "Game";
private float width; //Width of one tile
private float height; //Height of one tile
private final Game game;
Paint background = new Paint();
Paint dark = new Paint();
Paint light = new Paint();
Paint hilite = new Paint();
public GameView(Context context) {
super(context);
this.game = (Game) context;
setFocusable(true);
setFocusableInTouchMode(true);
Log.d(TAG, "GameView finished");
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
width = w / 10f;
height = h /10f;
Log.d(TAG, "onSizeChanged: width " + width + ", height " + height);
}
#Override
protected void onDraw(Canvas canvas) {
//Draw the background
background.setColor(getResources().getColor(R.color.background));
canvas.drawRect(0, 0, getWidth(), getHeight(), background);
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dark.setColor(getResources().getColor(Color.DKGRAY));
light.setColor(getResources().getColor(Color.LTGRAY));
hilite.setColor(getResources().getColor(Color.WHITE));
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Log.d(TAG, "Drawing...");
canvas.drawLine(0, i * height - 1, getWidth(), i * height - 1, light);
canvas.drawLine(0, i * width - 1, getHeight(), i * width - 1, light);
canvas.drawLine(0, i * height, getWidth(), i * height, hilite);
canvas.drawLine(0, i * width, getHeight(), i * width, hilite);
canvas.drawLine(0, i * height + 1, getWidth(), i * height + 1, dark);
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}
I have tried comparing the author's code to mine and except where I am not implementing features he is the codes seem to be matching.
However, the Log.d(TAG, "onSizeChanged: width " + width + ", height " + height); does not appear in LogCat so I assume this function is simply never called and I do not understand why.
You just create an instance of your GameView but you do not add it to your activity. Do this by using
setContentView(gameView);
in your onCreate method.
You need to set the view to the activity with setContentView(gameView) in onCreate of Game Activity.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "Game.onCreate called");
gameView = new GameView(this);
setContentView(gameView); // missing
...//rest of the code

Aspect ratio is off when scaling down and drawing a bitmap

The image I am using is from a 4x6. So the aspect ratio should be about .66. When I calculate the aspect ration in my code , I get around .66. However, the height of the displayed image looks squashed. The image only looks right if I set the aspect ratio manually to around .85.
Since setting the aspect ratio manually is not perfect, how can I get the can I keep the height of my image from appearing to be squashed.
public class SpotGameActivity extends Activity {
private Bitmap mBitmap;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.dpi2b);
setContentView(new BitMapView(this, mBitmap));
}
class BitMapView extends View {
Bitmap mBitmap = null;
public BitMapView(Context context, Bitmap bm) {
super(context);
mBitmap = bm;
}
#Override
protected void onDraw(Canvas canvas) {
// called when view is drawn
Paint paint = new Paint();
paint.setFilterBitmap(true);
// The image will be scaled so it will fill the width, and the
// height will preserve the image’s aspect ration
float aspectRatio = ((float) mBitmap.getWidth()) / mBitmap.getHeight();
Rect dest = new Rect(0, 0, this.getWidth(),(int) (this.getHeight() * aspectRatio));
String AR = Double.toString(aspectRatio);
//Rect dest = new Rect(0, 0, getWidth(), getHeight());
canvas.drawBitmap(mBitmap, null, dest, paint);
Toast.makeText(SpotGameActivity.this, AR, Toast.LENGTH_SHORT).show();
}
}
}
Aspect = width/height
newHeight = newWidth/Aspect
Do this,
Rect dest = new Rect(0, 0, this.getWidth(),(int) (this.getWidth() / aspectRatio));

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