Develop Reference

High resolution screen shot in Android

Is there any way to get a high resolution screen shot of a certain view in an activity.
I want to convert html content of my webview to PDF. For that I tried to take screen shot of the webview content and then converted it to PDF using itext. The resulted PDF is not in much more clarity.
My code:
protected void takeimg() {
Picture picture = mWebView.capturePicture();
Bitmap b = Bitmap.createBitmap(picture.getWidth(), picture.getHeight(),
Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
picture.draw(c);
// byte[] bt = b.getNinePatchChunk();
// Bitmap b;
// View v1 = mWebView.getRootView();
// v1.setDrawingCacheEnabled(true);
// b = Bitmap.createBitmap(v1.getDrawingCache());
// v1.setDrawingCacheEnabled(false);
FileOutputStream fos = null;
try {
File root = new File(Environment.getExternalStorageDirectory(),
"Sample");
if (!root.exists()) {
root.mkdir();
}
String sdcardhtmlpath = root.getPath().toString() + "/"
+ "temp_1.png";
fos = new FileOutputStream(sdcardhtmlpath);
// fos = openFileOutput("samsp_1.jpg", MODE_WORLD_WRITEABLE);
if (fos != null) {
b.compress(Bitmap.CompressFormat.PNG, 100, fos);
// fos.write(bt);
fos.close();
}
} catch (Exception e) {
Log.e("takeimg", e.toString());
e.printStackTrace();
}
}
protected void pdfimg() {
Document mydoc = new Document(PageSize.A3);
try {
File root = new File(Environment.getExternalStorageDirectory(),
"Sample");
if (!root.exists()) {
root.mkdir();
}
String sdcardhtmlpath = root.getPath().toString() + "/";
mydoc.setMargins(0, 0, 0, 0);
PdfWriter.getInstance(mydoc, new FileOutputStream(sdcardhtmlpath
+ PDFfilename));
mydoc.open();
Image image1 = Image.getInstance(sdcardhtmlpath + "temp_1.jpg");
image1.scalePercent(95f);
mydoc.add(image1);
// mydoc.newPage();
mydoc.close();
} catch (Exception e) {
Log.e("pdi name", e.toString());
}
}

Update: See Edit 3 for an answer to op's original question
There are two options:
Use a library to convert the HTML to PDF. This is by far the best option, since it will (probably) preserve text as vectors.
Get a high resolution render of the HTML and save it as a PNG (not PDF surely!).
For HTML to PDF, wkhtmltopdf looks like a good option, but it relies on Qt which you can't really use on Android. There are some other libraries but I doubt they do the PDF rendering very well.
For getting a high-res webview, you could try creating your own WebView and calling onMeasure(...) and onLayout(...) and pass appropriate parameters so the view is really big. Then call onDraw(myOwnCanvas) and the webview will draw itself to your canvas, which can be backed by a Bitmap using Canvas.setBitmap().
You can probably copy the state into the new WebView using something like
screenshotterWebview.onRestoreInstanceState(mWebView.onSaveInstanceState());
Orrr it may even be possible to use the same WebView, just temporarily resize it to be large, onDraw() it to your canvas, and resize it back again. That's getting very hacky though!
You might run into memory issues if you make it too big.
Edit 1
I thought of a third, exactly-what-you-want option, but it's kind of hardcore. You can create a custom Canvas, that writes to a PDF. In fact, it is almost easy, because underlying Canvas is Skia, which actually includes a PDF backend. Unfortunately you don't get access to it on Android, so you'll basically have to build your own copy of it on Android (there are instructions), and duplicate/override all the Canvas methods to point to your Skia instead of Androids. Note that there is a tempting Picture.writeToStream() method which serializes the Skia data, but unfortunately this format is not forwards or backwards compatible so if you use it your code will probably only work on a few versions of Android.
I'll update if/when I have fully working code.
Edit 2
Actually it is impossible to make your own "intercepting" Canvas. I started doing it and went through the tedious process of serializing all function calls. A few you can't do because they are hidden, but those didn't look important. But right at the end I came to serializing Path only to discover that it is write-only. That seems like a killer to me, so the only option is to interpret the result of Picture.writeToStream(). Fortunately there are only two versions of that format in use, and they are nearly identical.
Edit 3 - Really simple way to get a high resolution Bitmap of a view
Ok, it turns out just getting a high res bitmap of a view (which can be the entire app) is trivial. Here is how to get double resolution. Obviously all the bitmaps look a bit crap, but the text is rendered at full resolution:
View window = activity.getWindow().getDecorView()
Canvas bitmapCanvas = new Canvas();
Bitmap bitmap = Bitmap.createBitmap(window.getWidth()*2, window.getHeight()*2, Bitmap.Config.ARGB_8888);
bitmapCanvas.setBitmap(bitmap);
bitmapCanvas.scale(2.0f, 2.0f);
window.draw(bitmapCanvas);
bitmap.compress(Bitmap.CompressFormat.PNG, 0, myOutputStream);
Works like a charm. I've now given up on getting a PDF screenshot with vector text. It's certainly possible, but very difficult. Instead I am working on getting a high-res PSD where each draw operation is a separate layer, which should be much easier.
Edit 4
Woa this is getting a bit long, but success! I've generated an .xcf (GIMP) and PDF where each layer is a different canvas drawing operation. It's not quite as fine-grained as I was expecting, but still, pretty useful!
Actually my code just outputs full-size PNGs and I used "Open as layers..." and "Autocrop layer" in GIMP to make these files, but of course you can do that in code if you like. I think I will turn this into a blog post.
Download the GIMP or Photoshop demo file (rendered at 3x resolution).

When you capture the view, just screen bound will capture ( due to control weight and android render pipeline ).
Capturing screenshot for converting to PDF is tricky way. I think two way is more reasonable solutions.
Solution #1
Write a parser ( it's simple ) to convert webview content ( that is HTML ) to iText format.
You can refer to this article for more information.
http://www.vogella.com/articles/JavaPDF/article.html
Also to write a parser you can use REGEX and provide your own methods like parseTable, parseImage, ...
Solution #2 Internet Required
Provide a URL ( or webservice ) to convert HTML to PDF using PHP or C# that has a lot of nice libraries. Next you can send download link to the Client ( Android Device ).
So you can also dynamically add some Tags, Banners, ... to the PDF from server side.

Screen Shot is nothing but picture of your device display which usually depend upon your phone absolute pixels, if your phone is 480x800 screen shot will be same and generally applicable for all scenarios.

Sure, Use this:
Bitmap bitmap;
View v1 = MyView.getRootView();
v1.setDrawingCacheEnabled(true);
bitmap = Bitmap.createBitmap(v1.getDrawingCache());
v1.setDrawingCacheEnabled(false);
Here MyView is the View you need a screenshot of.

Custom method to draw drawables from assets folder has heigh cpu usage

I like to use the assets folder instead of the drawable folder (if it's not a nine-patch) because I can use multiple folders there. However the method I use to get an drawable required the cpu to do quiet a lot. For example: after adding 10 ImageViews need 10% CPU (I am using Android Assistent and Samsung TouchWiz TaskManager). I haven't notice it while I was writing a game. And now this game needs 40-100% CPU even if it isn't in the foreground.
That's the method I use to create an drawable:
public BitmapDrawable readAsset(path){
try{
inputStream = assetManager.open(path);
//get the Bitmap
desiredImg = BitmapFactory.decodeStream(inputStream, null, opts);
//resize for other screen sizes (scale is calculated beforehand)
scaleX =(int)(desiredImg.getWidth()/scale);
scaleY = (int)(desiredImg.getHeight()/scale);
//Bitmap to get config ARGB_8888 (createScaledBitmap returns RGB_565 => bad quality especially in gradients)
//create empty bitmap with Config.ARGB_8888 with the needed size for drawable
Bitmap temp = Bitmap.createBitmap(scaleX, scaleY, Config.ARGB_8888);
//Canvas to draw desiredImg on temp
Canvas canvas = new Canvas(temp);
canvas.drawBitmap(convert, null, new Rect(0, 0, scaleX, scaleY), paint);
//Convert to BitmapDrawable
BitmapDrawable bitmapDrawable=new BitmapDrawable(temp);
bitmapDrawable.setTargetDensity(metrics);
inputStream.close();
return bitmapDrawable;
}catch (Exception e) {
Log.d(TAG, "InputStream failed: "+e.getMessage());
}
return null;
}
The only thing I do in the app is adding some ImageViews in a RelativeLayout with this method:
private void addImageToContainer(int paddingLeft, int paddingTop) {
ImageView imageView = new ImageView(this);
imageView.setImageDrawable(assetReader.readAsset("test.jpg"));
imageView.setPadding(paddingLeft, paddingTop, 0, 0);
container.addView(imageView);
}

Probably the best thing for you to do would be to profile the execution with traceview, as this will give you a full understanding of where your app is spending most of its execution time. Then you can focus on optimizing that specific piece of code.
Just an educated guess, but I have a feeling that the majority of the wasted execution is not because you are pulling the images out of assets/ instead of resources, but all the scaling work being done afterwards (and from the looks of it, this is all being done on the main thread, so there's no concurrency to speak of).
I might recommend trying to leverage some of the BitmapFactory.Options (Docs link) available to you when you decode the asset. In particular, you should be able to do all the scaling you need with a combination of the inScaled, inDensity, and inTargetDensity options. If you pass these to your decodeStream() method, you could likely remove all the subsequent code used to resize the image before returning.

Android custom view save visible screen to bitmap

In my app the user manipulates a image, rotates, pinch, zoom etc. This is make within onDraw() using canvas.translate(), canvas.rotate() etc. Of course the image is big and after the manipulation of the image the user performs interactions with other Views. The thing is I don't want to redraw the whole big image over and over again only the visible part. So I'd like, after the user finishes operations, SAVE the current VISIBLE image on the screen to memory/bitmap/cache and redraw only that.
How can I achieve this ?

In the constructor of your custom View, enable the drawing cache like this: setDrawingCacheEnabled(true);. Then whenever you want to save the state of your Canvas you can call getDrawingCache(), which returns the desired Bitmap.
Documentation: getDrawingCache()

In your on draw initialize your Canvas with a bitmap.
keep a reference of this bitmap and save it whenever required.

I've found a really great article about what I needed HERE
To kepp thing clear, first I need to create a bitmap with the size of my View, then create a canvas for it, draw on canvas and then save it.
public void saveScreenshot() {
Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
canvas.draw(myGiganticImage)
File file = new File(context.getFilesDir() + "/cache.jpg");
FileOutputStream fos;
try {
fos = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fos);
fos.close();
cachedBackground = BitmapFactory.decodeFile(context.getFilesDir() + "/cache.jpg"
invalidate()
} catch (FileNotFoundException e) {
} catch (IOException e) {
}
}
I simply call this on onDraw() when I need it. It will save a bitmap on internal memory which I can use to draw, instead of the big picture.

Following may help you :
(1)
View v = view.getRootView();
v.setDrawingCacheEnabled(true);
Bitmap b = v.getDrawingCache();
(2) This is a similar to another question at How to capture the android device screen content?
(3) You can try using this library
http://code.google.com/p/android-screenshot-library/ It introduces an Android Screenshot Library (ASL) which enables to programmatically capture screenshots from Android devices without requirement of having root access privileges.

Resizing a screenshot to be attached to an email

I am currently building this Android application, where I will be taking a screenshot of a "TableLayout" and then emailing it as an attachment. Here is the part of the code which takes the screenshot.
However, when I try to attach the file, using the following code, it says that "File Size Too Large for Attachment". Can anyone suggest any other measures that I can take, apart from Bitmap.Compress, in order to make my file size even smaller? Thanks in advance!
private void getScreen()
{
View content = findViewById(R.id.TransactionLog);
content.setDrawingCacheEnabled(true);
content.buildDrawingCache(true);
Bitmap bitmap = Bitmap.createBitmap(content.getDrawingCache());
content.setDrawingCacheEnabled(false); // clear drawing cache
File file = new File(Environment.getExternalStorageDirectory() +
File.separator + "whatever2.png");
try
{
file.createNewFile();
FileOutputStream ostream = new FileOutputStream(file);
bitmap.compress(CompressFormat.PNG, 0, ostream);
ostream.flush();
ostream.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}

Try using Bitmap.createScaledBitmap:
public static Bitmap createScaledBitmap (Bitmap src, int dstWidth, int
dstHeight, boolean filter)
Since: API Level 1
Creates a new bitmap, scaled from an existing bitmap.
Parameters
src - The source bitmap.
dstWidth - The new bitmap's desired width.
dstHeight - The new bitmap's desired height.
filter - true if the source should be filtered.
FYI, the quality parameter passed to compress does not affect the file size when you are using CompressFormat.PNG. Try using CompressFormat.JPEG instead, then try different quality values.
Alternatively, try this:
http://thinkandroid.wordpress.com/2009/12/25/resizing-a-bitmap/

Have you tried use a higher value for the quality parameter? (currently you're using 0 and it could go up to 100).
I suggest trying 80.
boolean success = bitmap.compress(CompressFormat.PNG, 80, ostream);
Don't forget to test if it was successful (log the return value of that method).
You can also try to use another format (jpeg?).
To make things simpler, I suggest you to try to save it to the sdcard first and check if the size is something you'd be expecting. You might have some problem on the code that sends the email or it might not let you send large attachments.

How big is your image? An image made from an app, saved as a png, assuming its not a screenshot of a 'picture', should be pretty small. FAR smaller than what email should be able to accept, unless there's an arbitrarily small attachment size.
If what's in your table is an image, or has quite a bit of variance, you might consider jpeg instead of png. Otherwise, my guess is something else is going on.

Why is part of my bitmap image missing when written to external storage?

I want to send an image of a view to external storage so that it can be printed. The view is a grid made up of a tablelayout, tablerows and textviews. I write the view to the sdcard, then copy it to my HD using the DDMS file-explorer screen. But when I look at it in MS Paint, the image is only partially there.
I have tested this two ways.
When I usied the xml version, the result was a small black square – no detail, no grid, nothing.
Next I created a textview programmatically, with text using settext(“AAA”). The resulting bitmap had the correct color and size, but the text was missing.
Would someone please tell me how to get my view correctly written to external storage so that it looks like it does on the android screen?
//FYI. Here are excerpts from my program:
//Test-1 used the xml version of the grid:
TableLayout tl = (TableLayout) findViewById(R.id.board);
View viewToBeConverted = tl;
//Test-2 used a simple dynamically generated view:
TextView tv = new TextView(this);
tv.setBackgroundColor(Color.PINK);
tv.setTextColor(Color.BLACK);
tv.setText("AAA");
tv.setHeight(40);
tv.setWidth(40);
View viewToBeConverted = tv;
//Both Tests used this code to write to external storage:
try {
Bitmap returnedBitmap = Bitmap.createBitmap(40,40,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(returnedBitmap);
viewToBeConverted.draw(canvas);
String path = Environment.getExternalStorageDirectory() +
File.separator + strPuzSolFilename;
FileOutputStream out = new FileOutputStream(path);
} catch (Exception e) {
e.printStackTrace();
}

The documentation for draw says:
The view must have already done a full layout before this function is called.
Which means that you must call viewToBeConverted.layout(0,0,40,40) before you can call viewToBeConverted.draw(canvas).
EDIT: I will have to search more about Android's drawing before I can understand what is really happening in your example…
However, if you are simply looking for a way to get a Bitmap from a given View, I would suggest looking at the getDrawingCache() method.
For example:
viewToBeConverted.setDrawingCacheEnabled(true);
Bitmap returnedBitmap = viewToBeConverted.getDrawingCache(false);