CODEWITHSUNDEEP
javaandroidwebviewlayer
phibao37
phibao37

Reputation: 2350

WebView setLayerType LAYER_TYPE_HARDWARE not working

For performance perposes, I'm using LAYER_TYPE_HARDWARE for my WebView. But it doesn't work correctly.

enter image description here enter image description here

This is my code:

SmoothWebViewActivity.java

package uet.ducvu.androidexample;

import java.io.InputStream;
import java.util.Scanner;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.WindowManager;
import android.webkit.WebChromeClient;
import android.webkit.WebView;

public class SmoothWebViewActivity extends Activity {

    private WebView mWebView;
    private int mTextSize = 15;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_smooth_web_view);
        getWindow().setFlags(
                WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED,
                WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED);

        mWebView = (WebView) findViewById(R.id.my_web_view);
        mWebView.setWebChromeClient(new WebChromeClient());
        mWebView.getSettings().setJavaScriptEnabled(true);

        //mWebView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        mWebView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
    }

    public void loadText(View view){
        InputStream raw = getResources().openRawResource(R.raw.my_webview_template);
        Scanner scanner = new Scanner(raw).useDelimiter("\\A");
        String core = scanner.next();
        String body = "Some data here";

        scanner.close();
        for (int i = 0; i < 1000; i++)
            body += "<br/>" + i;
        String html = String.format(core, mTextSize, body);

        mWebView.loadDataWithBaseURL(null, html, null, "utf-8", null);
        System.out.println("Hardware: " + mWebView.isHardwareAccelerated());
    }

    public void changeSize(View view){
        mTextSize++;
        mWebView.loadUrl("javascript:dynamicChangeSize(" + mTextSize + ");");
    }
}

activity_smooth_web_view.xml

<LinearLayout 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"
    android:orientation="vertical"
    tools:context="uet.ducvu.androidexample.SmoothWebViewActivity"
    tools:ignore="HardcodedText,ButtonStyle" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:onClick="loadText"
            android:text="Load text" />

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:onClick="changeSize"
            android:text="Change size" />

    </LinearLayout>

    <WebView
        android:id="@+id/my_web_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

res/raw/my_webview_template.html

<html>
<head>
</head>

<body style="font-size:%dpx;">%s</body>

<script type="text/javascript">
function dynamicChangeSize(size){
    document.body.style.fontSize = size + "px";
}
</script>
</html>

AndroidManifest.xml

<activity
            android:name=".SmoothWebViewActivity"
            android:label="@string/title_activity_smooth_web_view"
            android:hardwareAccelerated="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

When i use View.LAYER_TYPE_SOFTWARE, everything works well. But, when i switch to View.LAYER_TYPE_HARDWARE, there are some problems:

Upvotes: 0

Views: 5812

Answers (1)

ChrisR
ChrisR

Reputation: 607

This is an old question, but I noticed that you have turned on hardware acceleration at the activity level in your manifest, the window level using WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED, and the View level using mWebView.setLayerType(View.LAYER_TYPE_HARDWARE, null);. Try only using the View level acceleration, or just the android:hardwareAccelerated="true" in the manifest. Not both, together.

From the Android developers page...

There are two different ways to check whether the application is hardware accelerated:

View.isHardwareAccelerated() returns true if the View is attached to a hardware accelerated window. Canvas.isHardwareAccelerated() returns true if the Canvas is hardware accelerated

I hope this helps someone.

Upvotes: 2

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