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_ff-addon-snippet-jniScreenshot - Shows how to take a native screenshot and draw it to HTML5 canvas. [jni] [canvas] [jsctypes] [android]
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// http://stackoverflow.com/questions/2661536/how-to-programatically-take-a-screenshot-on-android/16109978#16109978 | |
// public Bitmap screenShot(View view) { | |
// Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), | |
// view.getHeight(), Config.ARGB_8888); | |
// Canvas canvas = new Canvas(bitmap); | |
// view.draw(canvas); | |
// return bitmap; | |
// } | |
var my_jenv = null; | |
try { | |
my_jenv = JNI.GetForThread(); | |
var SIG = { | |
Bitmap: 'Landroid/graphics/Bitmap;', | |
Activity: 'Landroid/app/Activity;', | |
Bitmap_Config: 'Landroid/graphics/Bitmap$Config;', // `android.graphics.Bitmap.Config` in slash notation is with dollar sign as Config is subclass so use `android/graphics/Bitmap$Config` IMPORTANT: cannot even use the dot notation for LoadClass must use the slash slash dollar sign | |
Context: 'Landroid/content/Context;', | |
GeckoApp: 'Lorg/mozilla/gecko/GeckoApp;', | |
GeckoAppShell: 'Lorg/mozilla/gecko/GeckoAppShell;', | |
GeckoInterface: 'Lorg/mozilla/gecko/GeckoAppShell$GeckoInterface;', | |
int: 'I', | |
R: 'Landroid/R$id;', | |
View: 'Landroid/view/View;', // MUST USE `/`'s instead of `.`'s using dots is ok in the LoadClass, but in the method declaration its not and will cause crash | |
void: 'V', | |
Window: 'Landroid/view/Window;', | |
Canvas: 'Landroid/graphics/Canvas;', | |
Buffer: 'Ljava/nio/Buffer;', | |
ByteBuffer: 'Ljava/nio/ByteBuffer;', | |
byte: 'B' | |
}; | |
var View = JNI.LoadClass(my_jenv, SIG.View.substr(1, SIG.View.length - 2), { | |
methods: [ | |
{ name: 'getRootView', sig: '()' + SIG.View }, // http://developer.android.com/reference/android/view/View.html#getRootView%28%29 | |
{ name: 'getWidth', sig: '()' + SIG.int }, // http://developer.android.com/reference/android/view/View.html#getWidth%28%29 | |
{ name: 'getHeight', sig: '()' + SIG.int } // http://developer.android.com/reference/android/view/View.html#getHeight%28%29 | |
] | |
}); | |
var R = JNI.LoadClass(my_jenv, SIG.R.substr(1, SIG.R.length - 2), { | |
static_fields: [ | |
{ name: 'content', sig: SIG.int } // http://developer.android.com/reference/android/R.id.html#content | |
] | |
}); | |
var Activity = JNI.LoadClass(my_jenv, SIG.Activity.substr(1, SIG.Activity.length - 2), { | |
methods: [ | |
{ name: 'findViewById', sig: '(' + SIG.int + ')' + SIG.View }, // http://developer.android.com/reference/android/app/Activity.html#findViewById%28int%29 | |
{ name: 'getWindow', sig: '()' + SIG.Window } // http://developer.android.com/reference/android/app/Activity.html#getWindow%28%29 | |
] | |
}); | |
var Window = JNI.LoadClass(my_jenv, SIG.Window.substr(1, SIG.Window.length - 2), { | |
methods: [ | |
{ name: 'getDecorView', sig: '()' + SIG.View } // http://developer.android.com/reference/android/view/Window.html#getDecorView%28%29 | |
] | |
}); | |
var Bitmap_Config = JNI.LoadClass(my_jenv, SIG.Bitmap_Config.substr(1, SIG.Bitmap_Config.length - 2), { | |
static_fields: [ | |
{ name: 'ARGB_8888', sig: SIG.Bitmap_Config } | |
] | |
}); | |
var Bitmap = JNI.LoadClass(my_jenv, SIG.Bitmap.substr(1, SIG.Bitmap.length - 2), { | |
static_methods: [ | |
/* http://developer.android.com/reference/android/graphics/Bitmap.html#createBitmap%28int,%20int,%20android.graphics.Bitmap.Config%29 | |
* public static Bitmap createBitmap ( | |
* int width, | |
* int height, | |
* Bitmap.Config config | |
* ) | |
*/ | |
{ name: 'createBitmap', sig: | |
'(' + | |
SIG.int + // int width | |
SIG.int + // int height | |
SIG.Bitmap_Config + // Bitmap.Config config | |
')' + | |
SIG.Bitmap // return | |
} | |
], | |
methods: [ | |
/* http://developer.android.com/reference/android/graphics/Bitmap.html#getPixels%28int[],%20int,%20int,%20int,%20int,%20int,%20int%29 | |
* public void getPixels ( | |
* int[] pixels, | |
* int offset, | |
* int stride, | |
* int x, | |
* int y, | |
* int width, | |
* int height | |
* ) | |
*/ | |
{ name: 'getPixels', sig: | |
'(' + | |
'[' + SIG.int + // int[] pixels | |
SIG.int + // int offset | |
SIG.int + // int stride | |
SIG.int + // int x | |
SIG.int + // int y | |
SIG.int + // int width | |
SIG.int + // int height | |
')' + | |
SIG.void // return | |
}, | |
{ name: 'copyPixelsToBuffer', sig: | |
'(' + | |
SIG.Buffer + // Buffer dst | |
')' + | |
SIG.void // return | |
} | |
] | |
}); | |
var GeckoAppShell = JNI.LoadClass(my_jenv, SIG.GeckoAppShell.substr(1, SIG.GeckoAppShell.length - 2), { | |
static_methods: [ | |
{ name: 'getContext', sig: '()' + SIG.Context }, | |
{ name: 'getGeckoInterface', sig: '()' + SIG.GeckoInterface } | |
] | |
}); | |
var GeckoInterface = JNI.LoadClass(my_jenv, SIG.GeckoInterface.substr(1, SIG.GeckoInterface.length - 2), { | |
methods: [ | |
{ name: 'getActivity', sig: '()' + SIG.Activity } | |
] | |
}); | |
var GeckoApp = JNI.LoadClass(my_jenv, SIG.GeckoApp.substr(1, SIG.GeckoApp.length - 2), { | |
methods: [ | |
{ name: 'getContext', sig: '()' + SIG.Context }, | |
{ name: 'getActivity', sig: '()' + SIG.Activity } | |
] | |
}); | |
var Canvas = JNI.LoadClass(my_jenv, SIG.Canvas.substr(1, SIG.Canvas.length - 2), { | |
constructors: [ | |
{ name: '<init>', sig: '(' + SIG.Bitmap + ')V' }, // http://developer.android.com/reference/android/graphics/Canvas.html#Canvas%28android.graphics.Bitmap%29 | |
] | |
}); | |
var View = JNI.LoadClass(my_jenv, SIG.View.substr(1, SIG.View.length - 2), { | |
methods: [ | |
{ name: 'draw', sig: '(' + SIG.Canvas + ')V' }, // http://developer.android.com/reference/android/view/View.html#draw%28android.graphics.Canvas%29 | |
] | |
}); | |
var ByteBuffer = JNI.LoadClass(my_jenv, SIG.ByteBuffer.substr(1, SIG.ByteBuffer.length - 2), { | |
static_methods: [ | |
{ name: 'wrap', sig: '(' + '[' + SIG.byte + ')' + SIG.ByteBuffer } // actually never mind my thought was wrong: // link498066 - because of this i dont need a `JNI.LoadClass(my_jenv, '[' + SIG.byte);` in order to use `JNI.classes.byte.array` | |
] | |
}); | |
var geckoInterface = GeckoAppShell.getGeckoInterface(); | |
var activity = geckoInterface.getActivity(); | |
var win = activity.getWindow(); | |
var view = win.getDecorView(); | |
var rootView = view.getRootView(); | |
var width = rootView.getWidth(); | |
var height = rootView.getHeight(); | |
console.info('width:', width, 'height:', height); | |
var bmp = Bitmap.createBitmap(width, height, Bitmap_Config.ARGB_8888); | |
console.info('bmp:', bmp); | |
var canvas = Canvas['new'](bmp); | |
console.info('canvas:', canvas); | |
view.draw(canvas); | |
console.log('drwaing done'); | |
var imagedata = new ImageData(width, height); | |
var dataRef = imagedata.data; | |
///* getPixels method | |
JNI.LoadClass(my_jenv, '[' + SIG.int); | |
var IntArray = JNI.classes.int.array; | |
var pixels = IntArray.new(width * height); | |
//var pixels = JNI.jint.array(width * height)(); // bad way, caused crash | |
bmp.getPixels(pixels, 0, width, 0, 0, width, height); | |
console.info('pixels:', pixels['js#obj'].toString()); | |
console.time('getPixels post work'); | |
var pixels_data = pixels.getElements(0, pixels.length); | |
var j=0; | |
var numPixels = width * height; // pixels.length | |
for (var i=0; i<numPixels; i++) { | |
// var pixel = pixels.get(i); | |
var pixel = pixels_data[i]; | |
dataRef[j] = (pixel >> 16) & 0xff; // r | |
dataRef[j+1] = (pixel >> 8) & 0xff; // g | |
dataRef[j+2] = pixel & 0xff; // b | |
dataRef[j+3] = 255; // a | |
j += 4; | |
} | |
console.timeEnd('getPixels post work'); | |
//*/ | |
/* // copyPixelsToBuffer method | |
JNI.LoadClass(my_jenv, '[' + SIG.byte); // actually still needed despit so what i thought was wrong: // not needed because i loaded this in the methods above see link498066 | |
var ByteArray = JNI.classes.byte.array; | |
var rgba_arr = ByteArray.new(width * 4 * height); | |
var rgba_buf = ByteBuffer.wrap(rgba_arr); | |
bmp.copyPixelsToBuffer(rgba_buf); | |
console.time('copyPixelsToBuffer post work'); | |
var numPixels = width * height; // pixels.length | |
for (var i=0; i<numPixels; i=i+4) { | |
dataRef[i] = rgba_arr.get(i); | |
dataRef[i+1] = rgba_arr.get(i+1); | |
dataRef[i+2] = rgba_arr.get(i+2); | |
dataRef[i+3] = 255; | |
} | |
console.timeEnd('copyPixelsToBuffer post work'); | |
//*/ | |
var NS_HTML = 'http://www.w3.org/1999/xhtml'; | |
var aLinkedBrowser = BrowserApp._tabs[1]; | |
var aContentWindow = aLinkedBrowser.window; | |
var aContentDocument = aContentWindow.document; | |
var aCanvas = aContentDocument.createElementNS(NS_HTML, 'canvas'); | |
var aCtx = aCanvas.getContext('2d'); | |
aCanvas.width = width; | |
aCanvas.height = height; | |
aCtx.putImageData(imagedata, 0, 0); | |
// aCtx.fillStyle = 'rgba(0, 0, 0, 0.5)'; | |
// aCtx.fillRect(0, 0, width, height); | |
aContentDocument.documentElement.appendChild(aCanvas); | |
} finally { | |
if (my_jenv) { | |
JNI.UnloadClasses(my_jenv); | |
} | |
} |
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README
Rev1
{ name: 'ARGB_8888', sig: SIG.int }
if I remove that, it works fine, but I need this constantRev2
ARGB_8888
thing is outstanding fromRev1
, but I declaredcreateBitmap
appropriately nowRev3
Rev4
Rev5
bmp.getPixels....
need to fix thatRev6
width: 1280 height: 752
need to make that math faster, sometimes it crashes due to this math I think which is absolutely nuts