How to set the initial zoom/width for a webview

Question

I am trying to get the WebView to have similar behavior as the android browser. The browser opens all pages in a way that tries to fit their width to the screen. However, the default behavior of the WebView is to start at a 100% pixel scale so it starts zoomed in on the top left corner.

I have spent the last couple hours trying to find a way to get the WebView to scale the page to the screen like it does in the browser but I'm not having any luck. Has anyone found a way to accomplish this?

I see is a setting called setLoadWithOverviewMode, but that didn't appear to do anything at all. I also experimented with setInitialScale but on different screen sizes and web page sizes that won't be as graceful as the browsers scaling.

Any one have any leads?

Thanks

EDIT: Brian's method seems to work when the phone in landscape but not in portrait. In portrait it is close but still does not fit the whole screen in the page. I starting this bounty with the hope there is a sure-fire way to get the initial zoom to fit the page to the width of the page in any orientation or screen size.

Answer 1

The following code loads the desktop version of the Google homepage fully zoomed out to fit within the webview for me in Android 2.2 on an 854x480 pixel screen. When I reorient the device and it reloads in portrait or landscape, the page width fits entirely within the view each time.

BrowserLayout.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

     <WebView android:id="@+id/webview"
         android:layout_width="fill_parent"
         android:layout_height="fill_parent" />
</LinearLayout>

Browser.java:

import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebView;

public class Browser extends Activity {

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.BrowserLayout);

        String loadUrl = "http://www.google.com/webhp?hl=en&output=html";

        // initialize the browser object
        WebView browser = (WebView) findViewById(R.id.webview);

        browser.getSettings().setLoadWithOverviewMode(true);
        browser.getSettings().setUseWideViewPort(true);

        try {
            // load the url
            browser.loadUrl(loadUrl);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Answer 2

I figured out why the portrait view wasn't totally filling the viewport. At least in my case, it was because the scrollbar was always showing. In addition to the viewport code above, try adding this:

    browser.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
    browser.setScrollbarFadingEnabled(false);

This causes the scrollbar to not take up layout space, and allows the webpage to fill the viewport.

Hope this helps

Answer 3

It is and old question but let me add a detail just in case more people like me arrive here.

The excellent answer posted by Brian is not working for me in Jelly Bean. I have to add also:

browser.setInitialScale(30);

The parameter can be any percentage tha accomplishes that the resized content is smaller than the webview width. Then setUseWideViewPort(true) extends the content width to the maximum of the webview width.

Answer 4

Try using a wide viewport:

 webview.getSettings().setUseWideViewPort(true);

Answer 5

//for images and swf videos use width as "100%" and height as "98%"

mWebView2.getSettings().setJavaScriptEnabled(true);
mWebView2.getSettings().setLoadWithOverviewMode(true);
mWebView2.getSettings().setUseWideViewPort(true);
mWebView2.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
mWebView2.setScrollbarFadingEnabled(true);

Answer 6

I'm working with loading images for this answer and I want them to be scaled to the device's width. I find that, for older phones with versions less than API 19 (KitKat), the behavior for Brian's answer isn't quite as I like it. It puts a lot of whitespace around some images on older phones, but works on my newer one. Here is my alternative, with help from this answer: Can Android's WebView automatically resize huge images? The layout algorithm SINGLE_COLUMN is deprecated, but it works and I feel like it is appropriate for working with older webviews.

WebSettings settings = webView.getSettings();

// Image set to width of device. (Must be done differently for API < 19 (kitkat))
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
    if (!settings.getLayoutAlgorithm().equals(WebSettings.LayoutAlgorithm.SINGLE_COLUMN))
        settings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.SINGLE_COLUMN);
} else {
    if (!settings.getLoadWithOverviewMode()) settings.setLoadWithOverviewMode(true);
    if (!settings.getUseWideViewPort()) settings.setUseWideViewPort(true);
}

Answer 7

If you have the web view figured out but your images are still out of scale, the best solution I found (here) was simply prepending the document with:

<style>img{display: inline; height: auto; max-width: 100%;}</style>

As a result all images are scaled to match the web view width.