Develop Reference

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)

thumbnail reflection with Drawable instead of Bitmap

working on generate reflection for thumbnail in recent app menu
the code works very well with CM10 but since update to CM11 (kitkat) they moved to use Drawable instead of Bitmap for reduce memory usage
https://github.com/CyanogenMod/android_frameworks_base/commit/9926272f32868c858b24b45e048210cf3515741e
here should add the changes:
https://github.com/CyanogenMod/android_frameworks_base/blob/1e3c4a9e687b19cd7837fed51eb25e92a4f691c1/packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java#L509
here my code:
final int reflectionGap = 4;
int width = thumbnail.getWidth();
int height = thumbnail.getHeight();
Matrix matrix = new Matrix();
matrix.preScale(1, -1);
Bitmap reflectionImage = Bitmap.createBitmap(thumbnail, 0, height * 2 / 3, width, height/3, matrix, false);
Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height/3), Config.ARGB_8888);
Canvas canvas = new Canvas(bitmapWithReflection);
canvas.drawBitmap(thumbnail, 0, 0, null);
Paint defaultPaint = new Paint();
canvas.drawRect(0, height, width, height + reflectionGap, defaultPaint);
canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0, thumbnail.getHeight(), 0,
bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff, 0x00ffffff,
TileMode.CLAMP);
paint.setShader(shader);
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
canvas.drawRect(0, height, width,
bitmapWithReflection.getHeight() + reflectionGap, paint);
h.thumbnailViewImage.setImageBitmap(bitmapWithReflection);
my question is :
how i can make this code works with Drawable instead of Bitmap
thanks

try this:
Drawable drawable = getResources().getDrawable(R.drawable.ic_launcher);
int w = drawable.getIntrinsicWidth();
int h = drawable.getIntrinsicHeight();
drawable.setBounds(0, 0, w, h);
Bitmap b = Bitmap.createBitmap(w, h, Config.ARGB_8888);
Canvas c = new Canvas(b);
c.translate(0, h);
c.scale(1, -1);
drawable.draw(c);
// test it
ImageView iv = new ImageView(this);
iv.setImageBitmap(b);
setContentView(iv);

How to show reflection of coverflow widget in android?

hi in my project i've coverflow widget. i'm using code for that coverflow widget is in this link
this is the link i'm using
i want to implement reflection for that whole widget
thanks in advance
hi i'm using this method but not getting reflection,is any thing wrong in this? for coverflow widget
public boolean createReflectedImages() {
// The gap we want between the reflection and the original image
System.out.println(" i'm from createReflected image()");
final int reflectionGap = 4;//4
int index = 0;
for (int imageId : mImageIds)
{
Bitmap originalImage = BitmapFactory.decodeResource(
getResources(), imageId);
int width = originalImage.getWidth();
int height = originalImage.getHeight();
//int width=100;
//int height=100;
// This will not scale but will flip on the Y axis
Matrix matrix = new Matrix();
//matrix.preScale(-1.0f, 1.0f);
//Bitmap mirroredBitmap = Bitmap.createBitmap(originalImage, 0, 0, originalImage.getWidth(), originalImage.getHeight(), matrix, false);
matrix.preScale(1, -1);
// Create a Bitmap with the flip matrix applied to it.
// We only want the bottom half of the image
Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
height / 2, width, height / 2, matrix, false);
// Create a new bitmap with same width but taller to fit
// reflection
Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
(height + height / 2), Config.ARGB_8888);
// Create a new Canvas with the bitmap that's big enough for
// the image plus gap plus reflection
Canvas canvas = new Canvas(bitmapWithReflection);
// Draw in the original image
canvas.drawBitmap(originalImage, 0, 0, null);
// Draw in the gap
Paint deafaultPaint = new Paint();
canvas.drawRect(0, height, width, height + reflectionGap,
deafaultPaint);
// Draw in the reflection
canvas.drawBitmap(reflectionImage, 0, height + reflectionGap,
null);
// Create a shader that is a linear gradient that covers the
// reflection
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0,originalImage.getHeight(), 0,bitmapWithReflection.getHeight() + reflectionGap,
0x70ffffff, 0x00ffffff, TileMode.CLAMP);
// Set the paint to use this shader (linear gradient)
paint.setShader(shader);
// Set the Transfer mode to be porter duff and destination in
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
// Draw a rectangle using the paint with our linear gradient
canvas.drawRect(0, height, width,
bitmapWithReflection.getHeight() + reflectionGap, paint);
ImageView imageView = new ImageView(mContext);
imageView.setImageBitmap(bitmapWithReflection);
android.widget.Gallery.LayoutParams imgLayout = new CoverFlow.LayoutParams( 200, 200);
imageView.setLayoutParams(imgLayout);
imageView.setPadding(50, 100, 50, 20);
imageView.setScaleType(ScaleType.MATRIX);
mImages[index++] = imageView;
}
return true;

You can use This Coverflow in your project. It gives you option to add reflection in coverflow. I have used this in one of my previous apps
Edited -
Blog you have mentioned is using adapter which is extending BaseAdapter and is using createReflectedImages() method only
If you look into source code of link I have provided, there is CoverFlowTestingActivity is there which is using following code to setup coverflow
private void setupCoverFlow(final CoverFlow mCoverFlow, final boolean reflect) {
BaseAdapter coverImageAdapter;
if (reflect) {
coverImageAdapter = new ReflectingImageAdapter(new ResourceImageAdapter(this));
} else {
coverImageAdapter = new ResourceImageAdapter(this);
}
mCoverFlow.setAdapter(coverImageAdapter);
mCoverFlow.setSelection(2, true);
setupListeners(mCoverFlow);
}
Here you can see that if we want to reflection of images ReflectingImageAdapter in conjuction with ResourceImageAdapter which is extending AbstractCoverFlowImageAdapter.
I think this is the game changer for you

Add water effect on bitmap android

How can i add water waves in bitmap image?
i have found water ripple effect on touch event here: https://github.com/esteewhy/whater but can not implement on my single bitmap.
can anyone help in making water wave effect on my bitmap?
or should i go for image processing?
Thank you in advance.
Here is my sample code in which i have to make water reflection effect:
public static Bitmap reflection(Bitmap mainImage) {
int width = mainImage.getWidth();
int height = mainImage.getHeight();
Matrix matrix = new Matrix();
matrix.preScale(1, -1);
reflectionImage = Bitmap.createBitmap(mainImage, 0,
0, width, height , matrix, false);
reflectedBitmap = Bitmap.createBitmap(width,
(height + height), Config.ARGB_8888);
Canvas canvas = new Canvas(reflectedBitmap);
canvas.drawBitmap(mainImage, 0, 0, null);
Paint defaultPaint = new Paint();
canvas.drawRect(0, height, width, height, defaultPaint);
canvas.drawBitmap(reflectionImage, 0, height-6 , null);
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0,
mainImage.getHeight(), 0, reflectedBitmap.getHeight()
, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);
paint.setShader(shader);
paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
canvas.drawRect(0, height, width, reflectedBitmap.getHeight()
, paint);
return reflectedBitmap;
}

How to create white border around bitmap?

For example I want a white border of 10pixel around all 4 side of the bitmap. I am not using it for imageview
I am currently using this code to crop image. May I know how I could add a white border into it?
public Bitmap scaleCenterCrop(Bitmap source, int newHeight, int newWidth) {
int sourceWidth = source.getWidth();
int sourceHeight = source.getHeight();
// Compute the scaling factors to fit the new height and width, respectively.
// To cover the final image, the final scaling will be the bigger
// of these two.
float xScale = (float) newWidth / sourceWidth;
float yScale = (float) newHeight / sourceHeight;
float scale = Math.max(xScale, yScale);
// Now get the size of the source bitmap when scaled
float scaledWidth = scale * sourceWidth;
float scaledHeight = scale * sourceHeight;
// Let's find out the upper left coordinates if the scaled bitmap
// should be centered in the new size give by the parameters
float left = (newWidth - scaledWidth) / 2;
float top = (newHeight - scaledHeight) / 2;
// The target rectangle for the new, scaled version of the source bitmap will now
// be
RectF targetRect = new RectF(left, top, left + scaledWidth, top + scaledHeight);
// Finally, we create a new bitmap of the specified size and draw our new,
// scaled bitmap onto it.
Bitmap dest = Bitmap.createBitmap(newWidth, newHeight, source.getConfig());
Canvas canvas = new Canvas(dest);
canvas.drawBitmap(source, null, targetRect, null);
return dest;
}

I wrote a function for this:
private Bitmap addWhiteBorder(Bitmap bmp, int borderSize) {
Bitmap bmpWithBorder = Bitmap.createBitmap(bmp.getWidth() + borderSize * 2, bmp.getHeight() + borderSize * 2, bmp.getConfig());
Canvas canvas = new Canvas(bmpWithBorder);
canvas.drawColor(Color.WHITE);
canvas.drawBitmap(bmp, borderSize, borderSize, null);
return bmpWithBorder;
}
Basically it creates a new Bitmap adding 2 * bordersize to each dimension and then paints the original Bitmap over it, offsetting it with bordersize.

As for a way of doing this. You make your bitmap bigger than the one your adding to it and then fill the canvas with the background you want. If you need to add other effects you can look into the canvas options for clipping the rect and adding rounded corners and such.
RectF targetRect = new RectF(left+10, top+10, left + scaledWidth, top + scaledHeight);
Bitmap dest = Bitmap.createBitmap(newWidth+20, newHeight+20, source.getConfig());
Canvas canvas = new Canvas(dest);
canvas.drawColor(Color.WHITE);
canvas.drawBitmap(source, null, targetRect, null);

You can draw 4 rectangles after painting your bitmap's stuff.
point 0,0,3,sizey
point 0,0,sizex,3
point 0,sizey-3,sizex,sizey
point sizex-3,0,sizex,sizey

the accepted answer is nice but in the cases that bitmap contains a transparent background, it fills all over the background of source bitmap with white pixels. so it doesn't work fine for all cases.
a better way to achieve this goal is using Canvas#drawLine method like the following code:
Bitmap drawBorder(Bitmap source) {
int width = source.getWidth();
int height = source.getHeight();
Bitmap bitmap = Bitmap.createBitmap(width, height, source.getConfig());
Canvas canvas = new Canvas(bitmap);
Paint paint = new Paint();
paint.setStrokeWidth(50);
paint.setColor(Color.WHITE);
canvas.drawLine(0, 0, width, 0, paint);
canvas.drawLine(width, 0, width, height, paint);
canvas.drawLine(width, height, 0, height, paint);
canvas.drawLine(0, height, 0, 0, paint);
canvas.drawBitmap(source, 0, 0, null);
return bitmap;
}
in this way we first create a second bitmap using source bitmap width, height and config and use drawline() mathod four times to draw four lines using coordinates of end points of each line around the second bitmap and then draw the source bitmap on the second bitmap that must be returned.

A super easy way of doing it would be to set the ImageView background to white and add a padding value.
If that doesn't work, create a FrameLayout with w/h of wrap_content, set its background to white, put the ImageView in there, and set the ImageView's margins to the desired border width.

Its not elegant but you can always just draw a rectangle behind it, you already have the code to do this and any performance impact is going to be unnoticeable

You can create your targetRectangle 20px wider and 20px higher
RectF targetRect = new RectF(left, top, left + scaledWidth + 20, top + scaledHeight + 20);
and paint the background white

Try this it will also add border to your canvas
canvas.drawLine(0, 0, canvas.getWidth(), 0, paint2);
canvas.drawLine(0, 0, 0, canvas.getHeight(), paint2);
canvas.drawLine(0, canvas.getHeight(), canvas.getWidth(),
canvas.getHeight(), paint2);
canvas.drawLine(canvas.getWidth(), 0, canvas.getWidth(),
canvas.getHeight(), paint2);