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androidwebviewandroid-canvas

Programmatic scroll of Webview isn't reflected when drawing from Canvas

I'm extracting frames from a WebView in it's draw method and scrolling it programmatically. The problem is, no matter how big my bitmap is, I only get the output from the WebView based on its initial dimensions. the getHeight() returns a value of 1440 and that's all I can ever get from the WebView even if I make the bitmap larger and/or I scroll the WebView. this is its draw method:

@Override
public void draw( Canvas canvas ) {
    int height = getHeight();
    bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    newCanvas = new Canvas(bitmap);
    super.draw(newCanvas);
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
    array.Buffer = stream.toByteArray();
    mPluginInterfaceBitmap.onFrameUpdate(array, width, height);
    stream.reset();
}

I'm scrolling the webview like so:

mWebView.scrollBy(0,yScrollBy);

and I know it's scrolling because in subsequent frames I check:

mWebView.getScrollY()

My XML:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
<com.export.ian.webviewtest android:id="@+id/web_view"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

I've also tried increasing the size of the webview to match its ContentHeight but this never works and I'm not sure how it would work for infinte-scrolling websites. I want to be able to scroll the webview programmatically and extract the frame of whatever the user would see in the webpage.

This is what it looks like after scrolling a bit (ignore the angle of image)enter image description here

Solution

  • FINALLY found the answer from here:

    You have to call WebView.enableSlowWholeDocumentDraw() before inflating the view in your fragment.