Android clip canvas.drawBitmap - android

I am new to Android and I have two images one is an empty image and the other is a full image to represent a progress bar.
How can I only draw a percentage of the full image using canvas.drawBitmap?
I would prefer not to resize the bitmap image each time.

you can use 2 Rects, the source Rect and the destination Rect to only draw a piece
//example
bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.backbutton);
Rect source = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
Rect bitmapRect = new Rect(0, 0, canvasWidth -200,50);
canvas.drawBitmap(bitmap, source, bitmapRect, null);
a Rect is a rectangle like this
new Rect(topleftx,toplefty,bottomrightx,bottomrighty);

Related

how to add a photo in a desired position of a frame?

I am trying to :
Pick a photo from Android gallery (Suppose : person.png)
Cropping the photo as rounded image
Resize the image in 300x300 pixels
Then add the resized image(person.png) on the top of a frame image (frame.png). And the final resulted image will look like this (final_image.png)
Then, save the new image(final_image.png) into gallery with a new name.
person.png
frame.png
final_image.png
Here is my demo code for loading an image in a frame or mask.
ImageView mImageView= (ImageView)findViewById(R.id.imageview_id);
Bitmap original = BitmapFactory.decodeResource(getResources(),R.drawable.content_image);
Bitmap mask = BitmapFactory.decodeResource(getResources(),R.drawable.mask);
Bitmap result = Bitmap.createBitmap(mask.getWidth(), mask.getHeight(), Config.ARGB_8888);
Canvas mCanvas = new Canvas(result);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
mCanvas.drawBitmap(original, 0, 0, null);
mCanvas.drawBitmap(mask, 0, 0, paint);
paint.setXfermode(null);
mImageView.setImageBitmap(result);
mImageView.setScaleType(ScaleType.CENTER);
mImageView.setBackgroundResource(R.drawable.background_frame);

Stretch Rectangle and Fit Text on Multiple Lines in Canvas

I'm currently drawing a rectangle under a bitmap using the Canvas in Android. I am using the following code
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap bitmap = BitmapFactory.decodeFile(file.getPath(), options);
Bitmap b = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight() + 100, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
c.drawBitmap(bitmap, 0, 0, null);
Paint myPaint = new Paint();
myPaint.setColor(Color.rgb(0, 0, 0));
myPaint.setStrokeWidth(10);
Rect r = new Rect(0, bitmap.getHeight(), bitmap.getWidth(), bitmap.getHeight() + 100);
c.drawRect(r, myPaint);
Paint textPaint = new Paint();
textPaint.setTextSize(20);
textPaint.setColor(Color.WHITE);
textPaint.setTextAlign(Paint.Align.CENTER);
int width = r.width();
int numOfChars = textPaint.breakText(description,true,width,null);
int start = (altText.length()-numOfChars)/2;
c.drawText(description,start,start+numOfChars,r.exactCenterX(),r.exactCenterY(),textPaint);
iv.setImageBitmap(b);
The bitmap draws fine and the rectangle draws directly below it. The text draws centered inside the rectangle. My issue is that the text (which varies in length) draws outside the rectangle. What I would like to happen is have the text skip to a new line when it reaches the end of the rectangle (which is the same width as the bitmap)
This a xkcd comic reader, the alt text is the text I am trying to fit in the rectangle, the image is the comic itself which varies in width (and height)

set image inside circle shaped layout and hide overlapping part

I'm using frame layout and I've added imageview into it. frame layout is circled shape. the imageview inside frame layout moves outside of that circle when it's size gets bigger than layout size. I want to hide that extra imageview. any help would be much appreciated.
Thanks :)
Try this function...
You need to provide your square bitmap file and output size of the circle image you want.
public static Bitmap getCroppedBitmap(Bitmap bitmap, int size) {
bitmap = Bitmap.createScaledBitmap(bitmap, size, size, false);
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(output);
int color = 0xff424242;
Paint paint = new Paint();
Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawCircle(bitmap.getWidth() / 2, bitmap.getHeight() / 2,
bitmap.getWidth() / 2, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
return output;
}
Basically you should use canvas for this purpose.
Draw a circular canvas and add you image bitmap in it.
For your refs https://github.com/lopspower/CircularImageView
You can use this lib in your project
just add this in xml
<com.mikhaellopez.circularimageview.CircularImageView
android:layout_width="250dp"
android:layout_height="250dp"
android:src="#drawable/image"
app:border_color="#EEEEEE"
app:border_width="4dp"
app:shadow="true" />

Android: Positioning 2 bitmaps on a Canvas

I take picture and obtain a Bitmap (bitmap), when I take the picture there is an image I would like to stay on the top (bitmao2). So to save the picture with the image on it I use a canvas. I would like to position bitmap2 on bitmap exactly how it is positioned when I take the picture.
Here is what I do
Bitmap bitmap = BitmapFactory.decodeByteArray(data,0,data.length);
int width=bitmap.getWidth();
int height=bitmap.getHeight();
Bitmap bitmap2 = GameActivity.decodeSampledBitmapFromResource(gameactivity.getResources(), R.drawable.fire16,width1 );
Matrix matrix = new Matrix();
matrix.postRotate(90);
bitmap=Bitmap.createBitmap(bitmap,0,0,width,height,matrix,true);
ImageView image = (ImageView) gameactivity.findViewById(R.id.imageView4);
LayoutParams layout = (LayoutParams) image.getLayoutParams();
int margin = layout.topMargin;
Bitmap cs = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_4444);
Canvas canvas = new Canvas(cs);
canvas.drawBitmap(bitmap, 0f, 0f, null);
canvas.drawBitmap(bitmap2,0,margin, null);
(I rotate the image because it is in landscape mode even if I take it in portrait mode so I correct that)
The problem is even if dimensions Canvas = dimensions of bitmap, I don't see the entire image after my code is executed, it is a bit cropped and of course bitmap2 is not where it should be.
Maybe I should take the dimensions of the screen instead??
You can use drawBitmap (Bitmap bitmap, Rect src, Rect dst, Paint paint) for drawing bitmaps:
Rect src = new Rect(0, 0, bitmap2.getWidth(), bitmap2.getHeight());
Rect dst = new Rect(0, 0, width, height);
canvas.drawBitmap(bitmap2, src, dst, null);
Also if you rotating your image than width and height will be swapped here:
bitmap=Bitmap.createBitmap(bitmap,0,0,width,height,matrix,true);

Show portion of Bitmap image on canvas in Android

I am trying to build a Magnify tool in my Android app. For this, I have an ImageView, which I converted to Bitmap (with some zoom/scale factor).
imageView.setDrawingCacheEnabled(true);
Bitmap drawingCache = imageView.getDrawingCache(true);
Matrix matrix = new Matrix();
matrix.postScale(5, 5);
Bitmap viewCapture = Bitmap.createBitmap(drawingCache, 0, 0,
drawingCache.getWidth(),
drawingCache.getHeight(),
matrix, true);
imageView.setDrawingCacheEnabled(false);
Now, I am drawing this Bitmap image "viewCapture" to my canvas. Here, I want only portion of the image to be rendered on the canvas.
I tried using approaches: "setRectToRect() on Matrix", "canvas.drawBitmap(bitmap, src, dst, paint)". But, didn't work out appropriately.
Would using SurfaceViews be helpful? Has anyone come across this situation? Please post your thoughts/ideas.
Why not just use the following?
Canvas.drawBitmap(Bitmap bitmap, Rect src, RectF dst, Paint paint)
src corresponds to which region of the bitmap you want to draw and dst says where you want the bitmap drawn. You can read more about it here: http://developer.android.com/reference/android/graphics/Canvas.html
When I do that, I get a smaller image of the bitmap, instead of cropped image. Following is the snippet I have used.
Canvas c = holder.lockCanvas();
c.drawRGB(10, 10, 10);
Rect src = new Rect((int)x - _image.getWidth(), (int) y - _image.getHeight(), (int)x + _image.getWidth(), (int) y + _image.getHeight());
RectF dst = new RectF((int)x - 50, (int) y - 50, (int)x + 50, (int) y + 50);
c.drawBitmap(_image, src, dst, null);
holder.unlockCanvasAndPost(c);

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