Develop Reference

Android Creating an image from an API response [duplicate]

I need to create .jpeg/.png file on my Android application programmatically. I have simple image (black background), and it need to write some text on it programmatically. How can I do it? Is it possible?

It's definately possible.
To write text on an image you have to load the image in to a Bitmap object. Then draw on that bitmap with the Canvas and Paint functions. When you're done drawing you simply output the Bitmap to a file.
If you're just using a black background, it's probably better for you to simply create a blank bitmap on a canvas, fill it black, draw text and then dump to a Bitmap.
I used this tutorial to learn the basics of the canvas and paint.
This is the code that you'll be looking for to turn the canvas in to an image file:
OutputStream os = null;
try {
File file = new File(dir, "image" + System.currentTimeMillis() + ".png");
os = new FileOutputStream(file);
finalBMP.compress(CompressFormat.PNG, 100, os);
finalBMP.recycle(); // this is very important. make sure you always recycle your bitmap when you're done with it.
screenGrabFilePath = file.getPath();
} catch(IOException e) {
finalBMP.recycle(); // this is very important. make sure you always recycle your bitmap when you're done with it.
Log.e("combineImages", "problem combining images", e);
}

Yes, see here
Bitmap b = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
You can also use awt's Graphics2D with this compatibility project

Using Graphics2d you can create a PNG image as well:
public class Imagetest {
public static void main(String[] args) throws IOException {
File path = new File("image/base/path");
BufferedImage img = new BufferedImage(100, 100,
BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = img.createGraphics();
g2d.setColor(Color.YELLOW);
g2d.drawLine(0, 0, 50, 50);
g2d.setColor(Color.BLACK);
g2d.drawLine(50, 50, 0, 100);
g2d.setColor(Color.RED);
g2d.drawLine(50, 50, 100, 0);
g2d.setColor(Color.GREEN);
g2d.drawLine(50, 50, 100, 100);
ImageIO.write(img, "PNG", new File(path, "1.png"));
}
}

Save layout as an image

I have a LinearLayout and I am want to save the contents of that view as an image. I have it half working.
File imageFile;
// image naming and path to include sd card appending name you choose for file
String mPath = Environment.getExternalStorageDirectory().toString() + "/a.png";
// create bitmap screen capture
View v1 = getWindow().getDecorView().getRootView();
Bitmap bitmap;
v1.setDrawingCacheEnabled(true);
bitmap = Bitmap.createBitmap(v1.getDrawingCache());
v1.setDrawingCacheEnabled(false);
OutputStream fout = null;
imageFile = new File(mPath);
try {
fout = new FileOutputStream(imageFile);
bitmap.compress(Bitmap.CompressFormat.PNG, 10, fout);
fout.flush();
fout.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
With the above code it will save a copy of the view, but only what's seen on the device screen. I have more information on the view that I want saved. The code above from here and this will only save the information seen on the screen as an image. I want all the information saved, even the information that is not on the screen (where you need to scroll to see).
How can I achieve that?

Another option is to use:
Bitmap b = Bitmap.createBitmap(width, height....)
v1.setLayoutParams // Full width and height of content
Canvas c = new Canvas(b);
v1.draw(c); // You now have full bitmap
saveBitmap(b);

Run a measure/layout pass on it and draw it to a canvas. Suppose your parent was called "view" and was a vertical LinearLayout:
view.measure(someWidth, MeasureSpec.UNSPECIFIED);
Bitmap bitmap = Bitmap.createBitmap(view.getMeasuredWidth(), view.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bitmap);
view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
view.draw(c);

fetching the drawing done on canvas using getRootView

I am using MyView for drawing content on a canvas using FingerPaint API demo app. I want to capture whatever I have written on the canvas. But when I use View v1 = myview.getRootView() it is returning only the blank canvas and not the content. I want to save my drawing in SDCard. Following is my code. Let me know what do i need to change
v1 = myview.getRootView();
System.out.println("v1 value = "+v1);
v1.buildDrawingCache(true);
v1.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
//v1.layout(0, 0, v1.getMeasuredWidth(), v1.getMeasuredHeight());
v1.layout(0, 0, 100, 100);
//Bitmap b = Bitmap.createBitmap(v1.getDrawingCache());
myview.mBitmap = Bitmap.createBitmap(v1.getDrawingCache());
System.out.println("BITMAP VALue = "+myview.mBitmap);
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
//b.compress(Bitmap.CompressFormat.JPEG, 40, bytes);
File f = new File(Environment.getExternalStorageDirectory()+ File.separator + "test.jpg");
try {
f.createNewFile();
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
} catch (Exception e)
{
e.printStackTrace();
}
v1.setDrawingCacheEnabled(false);
myview is an object of class MyView that extends View.

you can directly use the myview object to get the current view/canvas
myview.setDrawingCacheEnabled(true);
Bitmap b = myview.getDrawingCache();
for immutable image use this
Bitmap b = myview.getDrawingCache().copy(Config.ARGB_8888, true);
and then you can save this bitmap as image file

Bitmap not saved correctly (from Android's Canvas)

I changed my question a bit.
EDIT:
// make textures from text
public static void createTextureFromText(GL10 gl, String text, String texName) {
Paint p = new Paint();
p.setColor(Color.GREEN);
p.setTextSize(32 * getResources().getDisplayMetrics().density);
// get width and height the text takes (in px)
int width = (int) p.measureText(text);
int height = (int) p.descent();
// Create an empty, mutable bitmap based on textsize
Bitmap bmp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_4444);
// get a canvas to paint over the bitmap
Canvas canvas = new Canvas(bmp);
bmp.eraseColor(Color.CYAN); //Cyan for debugging purposes
//draw the text
canvas.drawText(text, 0, 0, p);
// save image - for debugging purposes
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.JPEG, 40, bytes);
// create a new file name "test.jpg" in sdcard
File f = new File(Environment.getExternalStorageDirectory() + File.separator + "test.jpg");
try {
f.createNewFile();
// write the bytes in file
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
fo.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
.... make texture
}
I now have this code in use for creating textures from given text (this is just partially).
But I found the fault lies somewhere in the Bitmap creation. I now save the Bitmap on the sd-card, to see how it turns out and found I get a ALL Cyan bitmap (672B, 164x7 are the dimensions).
Does Anyone see why it doesn't create an Bitmap with text on it? What can I be doing wrong?
You'll be a hero if you could help me :)

Firstly, your text height calculation is wrong. The 'descent' measurement is just the portion of text below the baseline (i.e. the tails of 'g' and 'q' etc). The correct height is ascent+descent, except that since ascent is negative you want:
int height = (int) (p.descent() + -p.ascent());
Secondly, when you drawText() the y coordinate you give it is where the baseline goes, it is not the top or bottom edge. So if you want to fill a bitmap that's just big enough to hold the text, your y coordinate should also be -p.ascent().

How to Save the drawing canvas in android?

I am using this API demo of the Developer site, THIS DEMO.
But i am wonder that how to save that image in to My Andrtoid Device.
Is please anyone give the Code to save that drawn image to the Android Device.
Thanks.

try this code
View content = your_view;
content.setDrawingCacheEnabled(true);
content.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
Bitmap bitmap = content.getDrawingCache();
String path = Environment.getExternalStorageDirectory().getAbsolutePath();
File file = new File(path+"/image.png");
FileOutputStream ostream;
try {
file.createNewFile();
ostream = new FileOutputStream(file);
bitmap.compress(CompressFormat.PNG, 100, ostream);
ostream.flush();
ostream.close();
Toast.makeText(getApplicationContext(), "image saved", 5000).show();
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "error", 5000).show();
}

drawView.setDrawingCacheEnabled(true);
Bitmap bm = null;
drawView.destroyDrawingCache();
bm=drawView.getDrawingCache();
Then write the bitmap to file using bitmap factory.

One option is create another Canvas (as shown below) and repeat all your drawing on this new canvas.
Once done, call drawBitmap.
Bitmap bitmap = new Bitmap(// Set the params you like //);
Canvas canvas = new Canvas(bitmap);
// Do all your drawings here
canvas.drawBitmap(// The first picture //);
The best would be if there was a way to copy an existing canvas and then you wont need to re-draw everything but I couldn't find one.

I have implemented the below approach & worked for me.
Get your CustomView by using its id from xml file but not by instantiating the Customview.
View v = findViewById(R.id.custom_view);
//don't get customview by this way, View v = new CustomView(this);
int canvasWidth = v.getWidth();
int canvasHeight = v.getHeight();
Bitmap bitmap = Bitmap.createBitmap(canvasWidth, canvasHeight, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
v.draw(canvas);
ImageView imageView = findViewById(R.id.image_view);
imageView.setImageBitmap(bitmap);
All code should be inside saveButton click listener.