Develop Reference

Android - Any library for adding repost label to bitmap

I have been trying to make a photo sharing app, with the ability to add your image and name to the image. I have been messing with Canvas for the whole day, but couldn't get good results. I was able to draw the name and bitmap, but they didn't look so good.
That's why I am here asking about is there any library or piece of code that could help me in making something similar to [this][1]. I wasn't able to find any thing for it.
EDIT: Sorry for not adding my own code
Here is my code from my latest try
public void AddText(Position2D pos){
//Position2D is an enum having the 4 corners of the image
bmWorking= bmOriginal.copy(Bitmap.Config.ARGB_8888,true);
Canvas canvas = new Canvas(bmWorking);
Paint paint = new Paint();
paint.setColor(Color.WHITE);
paint.setStyle(Paint.Style.FILL);
Paint textPaint = new Paint();
textPaint.setColor(Color.BLACK);
float width = (35f/100f) * bmWorking.getWidth();
float height = (width/16f) * 3;
textPaint.setTextSize(height - 4); //I wanted to have some space (margin) above and below the text
textPaint.setTextAlign(Paint.Align.LEFT);
float [] coords = getPositionCoords(pos, width, height); //getPositionCoords returns a float array with the Left,Top,Right,Bottom position calculated based on the width and height
canvas.drawRect(coords[0],coords[1], coords[2], coords[3],paint);
username = "Haider Ali Punjabi";
canvas.drawText(username, coords[0] ,coords[3], textPaint);
bitmapView.setImageBitmap(bmWorking);
}
Here is the result
UPDATE:
#pskink gave me this code
which works nicely

if you want to customize it, then instead of solid white rectangle (like in your original code) use a Drawable and the result could be something like this:
the code:
// for int gravity: see android.view.Gravity, like Gravity.LEFT, Gravity.BOTTOM, etc
// for example:
// Bitmap out = addText(this, in, "Haider Ali Punjabi", android.R.drawable.alert_light_frame, Gravity.BOTTOM, new Point(10, 10));
public Bitmap addText(Context ctx, Bitmap in, String text, int resId, int gravity, Point pad) {
if (pad == null) pad = new Point();
Bitmap out = in.copy(Bitmap.Config.ARGB_8888, true);
Canvas canvas = new Canvas(out);
Paint textPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
textPaint.setColor(Color.BLACK);
textPaint.setTextAlign(Paint.Align.LEFT);
// textPaint.setTextSize(128);
Rect inBounds = new Rect();
textPaint.getTextBounds(text, 0, text.length(), inBounds);
float scale = out.getWidth() * 0.35f / inBounds.width();
Rect container = new Rect(0, 0, out.getWidth(), out.getHeight());
Rect outBounds = new Rect();
int w = (int) (inBounds.width() * scale);
int h = (int) (inBounds.height() * scale);
Gravity.apply(gravity, 2 * pad.x + w, 2 * pad.y + h, container, outBounds);
Drawable dr = ctx.getResources().getDrawable(resId);
Rect padding = new Rect();
dr.getPadding(padding);
dr.setBounds(outBounds.left - padding.left, outBounds.top - padding.top, outBounds.right + padding.right, outBounds.bottom + padding.bottom);
dr.draw(canvas);
Matrix matrix = new Matrix();
RectF src = new RectF(inBounds);
RectF dst = new RectF(outBounds);
dst.inset(pad.x, pad.y);
matrix.setRectToRect(src, dst, Matrix.ScaleToFit.CENTER);
canvas.concat(matrix);
canvas.drawText(text, 0, 0, textPaint);
return out;
}

How to show Android SeekBar progressChanged value inside SeekBar thumb?

I want to show the value of the current progress point in the thumb of an Android SeekBar. This is what I have tried so far:
SeekBar progBar = (SeekBar)FindViewById(Resource.Id.seekBar1);
progBar.ProgressChanged += (object sender, SeekBar.ProgressChangedEventArgs e) =>
{
if (e.FromUser)
{
Drawable d = ContextCompat.GetDrawable(this, Resource.Drawable.thumb);
Bitmap bitmap = BitmapFactory.DecodeResource(Resources, Resource.Drawable.thumb);
Bitmap bmp = bitmap.Copy(Bitmap.Config.Argb8888, true);// this line gives me a System.NullReferenceException: Object reference not set to an instance of an object. error
Canvas c = new Canvas(bmp);
Canvas c = new Canvas(bmp);
string text = Integer.ToString(progBar.Progress);
Paint p = new Paint();
p.SetTypeface(Typeface.DefaultBold);
p.TextSize = 14;
p.Color = Color.White;
int width = (int)p.MeasureText(text);
int yPos = (int)((c.Height / 2) - ((p.Descent() + p.Ascent()) / 2));
c.DrawText(text, (bmp.Width - width) / 2, yPos, p);
progBar.SetThumb(new BitmapDrawable(Resources, bmp));
}
};
Then when I got the type of Drawable d, it's a Gradient Drawable. I researched but I couldn't find a way to convert a gradient Drawable to bitmap.

Drawable d = ContextCompat.GetDrawable(this, Resource.Drawable.thumb);
Canvas c = new Canvas();
Bitmap bitmap = Bitmap.CreateBitmap(d.IntrinsicWidth, d.IntrinsicHeight, Bitmap.Config.Argb8888);
c.SetBitmap(bitmap);
d.SetBounds(0, 0, d.IntrinsicWidth, d.IntrinsicHeight);
d.Draw(c);
//Bitmap bmp = bitmap.Copy(Bitmap.Config.Argb8888, true);
string text = Integer.ToString(progress) + "%";
Paint p = new Paint();
p.SetTypeface(Typeface.CreateFromAsset(Assets, "fonts/Brandon_bld.otf"));
p.TextSize = 18;
p.Color = Color.White;
int width = (int)p.MeasureText(text);
int yPos = (int)((c.Height / 2) - ((p.Descent() + p.Ascent()) / 2));
c.DrawText(text, (bitmap.Width - width) / 2, yPos, p);
progBar.SetThumb(new BitmapDrawable(Resources, bitmap));
using the canvas to create the bitmap worked

Drawing Oval on canvas with PAINT object in Android

In the following code, I'm trying to draw an oval which be enlarged with time.
Bitmap currBitmap = null;
Canvas currCanvas = null;
//Config Paint Case2
final Paint currPaint = new Paint();
List BlocksList = null;
boolean bSet = false;
public void DrawOval(Bitmap src, int nRadiusprct)
{
// image size
int width = src.getWidth();
int height = src.getHeight();
//create bitmap output
if(currBitmap == null)
currBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
// set canvas for painting
if(currCanvas == null)
{
currCanvas = new Canvas(currBitmap);
currCanvas.drawARGB(0, 0, 0, 0);
MainActivity.imgMain.setImageBitmap(currBitmap);
}
// config paint Case1
/*final Paint currPaint = new Paint();
currPaint.setAntiAlias(true);
currPaint.setColor(Color.BLACK);*/
// config paint Case2
if(!bSet)
{
currPaint.setAntiAlias(true);
currPaint.setColor(Color.BLACK);
// create Xfer mode
currPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
bSet = true;
}
// config rectangle for embedding
int nMidWidth = width/2;
int nMidHeight = height/2;
float fPercent = (nRadiusprct / 100.0f);
float fLeft = nMidWidth * (1 - fPercent);
float fRight = nMidWidth * (1 + fPercent);
float fTop = nMidHeight * (1 - fPercent);
float fBottom = nMidHeight * (1 + fPercent);
final Rect rect = new Rect(0, 0, width, height);
final RectF rectF = new RectF(fLeft, fTop, fRight, fBottom);
currCanvas.drawOval(rectF, currPaint);
// create Xfer mode, Config Paint Case1
//currPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
currCanvas.drawBitmap(src, rect, rect, currPaint);
MainActivity.imgMain.invalidate();
}
Now, As you can see write a comment "Config Paint Case1" or "Config Paint Case2", case1 represents the case where I create a paint instance each time the method is called, while case 2 represents where I define a member object in the class so I can use it whenever I need, the problem that when I'm using the first case everything is working perfectly and accurate, while when I'm using the second case nothing happened, The main thing that in my opinion I don't need to create a paint object each time so I need to optimize my code more and more, but why this happened here.....

Finally I got an answer to this question, A great help by this article Transparency with JPEGs done right that describes how PorterDuff modes are work, In that article I found this Xfermodes Example which gives me where is the error and here is the description.
Actually, I don't need to create a paint object everytime, what I need is to deal with the xfermodes in a correct way, the perfect code is:
Bitmap currBitmap = null;
Canvas currCanvas = null;
//Config Paint Case2
final Paint currPaint = new Paint();
List BlocksList = null;
boolean bSet = false;
public void DrawOval(Bitmap src, int nRadiusprct)
{
// image size
int width = src.getWidth();
int height = src.getHeight();
//create bitmap output
if(currBitmap == null)
currBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
// set canvas for painting
if(currCanvas == null)
{
currCanvas = new Canvas(currBitmap);
MainActivity.imgMain.setImageBitmap(currBitmap);
}
// config paint Case2
if(!bSet)
{
currPaint.setAntiAlias(true);
currPaint.setColor(Color.BLACK);
bSet = true;
}
// config rectangle for embedding
int nMidWidth = width/2;
int nMidHeight = height/2;
float fPercent = (nRadiusprct / 100.0f);
float fLeft = nMidWidth * (1 - fPercent);
float fRight = nMidWidth * (1 + fPercent);
float fTop = nMidHeight * (1 - fPercent);
float fBottom = nMidHeight * (1 + fPercent);
final Rect rect = new Rect(0, 0, width, height);
final RectF rectF = new RectF(fLeft, fTop, fRight, fBottom);
Xfermode BeforEPaintXferMode = currPaint.getXfermode();
currCanvas.drawOval(rectF, currPaint);
// create Xfer mode
currPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
// draw source image to canvas
currCanvas.drawBitmap(src, rect, rect, currPaint);
currPaint.setXfermode(BeforEPaintXferMode);
MainActivity.imgMain.invalidate();
}
Now, as you can see I just storing the current xfermode before painting, then I set it to SRC_IN mode and finally, I go back to the original one. and everything is working perfectly.

Android QuickContactBadge with letters like Android Lollipop

I have a list of contacts and I want to show in each contact's QuickContactBadge the first letter of his name.
Can I create the images in runtime?
This is like Android Lollipop, where contacts and dialer uses QuickContactBadge with letters:

I use a function to generate these images.
public static Bitmap generateCircleBitmap(Context context, int circleColor, float diameterDP, String text){
final int textColor = 0xffffffff;
DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
float diameterPixels = diameterDP * (metrics.densityDpi / 160f);
float radiusPixels = diameterPixels/2;
// Create the bitmap
Bitmap output = Bitmap.createBitmap((int) diameterPixels, (int) diameterPixels,
Bitmap.Config.ARGB_8888);
// Create the canvas to draw on
Canvas canvas = new Canvas(output);
canvas.drawARGB(0, 0, 0, 0);
// Draw the circle
final Paint paintC = new Paint();
paintC.setAntiAlias(true);
paintC.setColor(circleColor);
canvas.drawCircle(radiusPixels, radiusPixels, radiusPixels, paintC);
// Draw the text
if (text != null && text.length() > 0) {
final Paint paintT = new Paint();
paintT.setColor(textColor);
paintT.setAntiAlias(true);
paintT.setTextSize(radiusPixels * 2);
Typeface typeFace = Typeface.createFromAsset(context.getAssets(),"fonts/Roboto-Thin.ttf");
paintT.setTypeface(typeFace);
final Rect textBounds = new Rect();
paintT.getTextBounds(text, 0, text.length(), textBounds);
canvas.drawText(text, radiusPixels - textBounds.exactCenterX(), radiusPixels - textBounds.exactCenterY(), paintT);
}
return output;
}
I pass the contact's name into the following getMaterialColor function to select a color.
private static List<Integer> materialColors = Arrays.asList(
0xffe57373,
0xfff06292,
0xffba68c8,
0xff9575cd,
0xff7986cb,
0xff64b5f6,
0xff4fc3f7,
0xff4dd0e1,
0xff4db6ac,
0xff81c784,
0xffaed581,
0xffff8a65,
0xffd4e157,
0xffffd54f,
0xffffb74d,
0xffa1887f,
0xff90a4ae
);
public static int getMaterialColor(Object key) {
return material.get(Math.abs(key.hashCode()) % materialColors.size());
}

How to convert color image bitmap to black&white image bitmap in android?

In my Business Card Reader android application, I need to convert color image bitmap to black & white image bitmap (not gray scale image) for OCR text reading. so please help me to to convert color image bitmap to black & white image bitmap in android.

This question is long ago, but probably I could help other users.
I also had a long search for creating (fast)a pure Black and White bitmap.
My first methode used bitmap.getPixel() and bitmap.setPixel()
This took about 8s (832 x 1532)
New Method took 0.4s! Thanks factor 20!
Now I load all Pixels in an int array and go so through all pixels with getPixels(..) and setPixels(..):
Here my method:
public static Bitmap createBlackAndWhite(Bitmap src) {
int width = src.getWidth();
int height = src.getHeight();
Bitmap bmOut = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
final float factor = 255f;
final float redBri = 0.2126f;
final float greenBri = 0.2126f;
final float blueBri = 0.0722f;
int length = width * height;
int[] inpixels = new int[length];
int[] oupixels = new int[length];
src.getPixels(inpixels, 0, width, 0, 0, width, height);
int point = 0;
for(int pix: inpixels){
int R = (pix >> 16) & 0xFF;
int G = (pix >> 8) & 0xFF;
int B = pix & 0xFF;
float lum = (redBri * R / factor) + (greenBri * G / factor) + (blueBri * B / factor);
if (lum > 0.4) {
oupixels[point] = 0xFFFFFFFF;
}else{
oupixels[point] = 0xFF000000;
}
point++;
}
bmOut.setPixels(oupixels, 0, width, 0, 0, width, height);
return bmOut;
}

You could convert the image applying a color filter in this way:
Bitmap bwBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bwBitmap );
//set contrast
ColorMatrix contrastMatrix = new ColorMatrix();
//change contrast
float contrast = 50.f;
float shift = (-.5f * contrast + .5f) * 255.f;
contrastMatrix .set(new float[] {
contrast , 0, 0, 0, shift ,
0, contrast , 0, 0, shift ,
0, 0, contrast , 0, shift ,
0, 0, 0, 1, 0 });
//apply contrast
Paint contrastPaint = new Paint();
contrastPaint.setColorFilter(new ColorMatrixColorFilter(contrastMatrix ));
canvas.drawBitmap(colorBitmap, 0, 0, contrastPaint);
//set saturation
ColorMatrix saturationMatrix = new ColorMatrix();
saturationMatrix.setSaturation(0); //you set color saturation to 0 for b/w
//apply new saturation
Paint saturationPaint = new Paint();
saturationPaint.setColorFilter(new ColorMatrixColorFilter(saturationPaint));
canvas.drawBitmap(colorBitmap, 0, 0, saturationPaint);

You need to use ColorMatrix and ColorFilterclass in android to convert to Black and White.
Use this ColorMatrix - ColorMatrix cm1 = new ColorMatrix(new float[]{0.5f,0.5f,0.5f,0,0,
0.5f,0.5f,0.5f,0,0,
0.5f,0.5f,0.5f,0,0,
0,0,0,1,0,0,
0,0,0,0,1,0
});