SetSize WebView Android

Question

I am having an issue with A webView not re-sizing. Im not exactly sure how to approach this problem. I have a webView with A custom webViewClient above a ListView in my application. The WebView has a dynamic accordion within it. When i click the accordion it expands, when i click it again it either expands again or retracts.

The problem i am having is that while the content retracts, the webView stays at its expanded size, resulting in a lot of white space at the bottom of my webView. Is there a way to call invalidate or setHeight in an ontouch method of the webView that does reload the webView? Or some override method in the webViewClient that can handle this?

And what is the layout which webView is in? – sygi Mar 25 '14 at 09:42 — sygi, Mar 25 '14 at 09:42
the WebView is within a vertical LinearLayout. – sirFunkenstine Mar 25 '14 at 09:46 — sirFunkenstine, Mar 25 '14 at 09:46

score 1 · Answer 1 · answered Mar 25 '14 at 11:14

I'm guessing you have height set to 'wrap_content'. The behavior you'r observing is because of a bug in the WebView and has been fixed in 4.4 (KitKat).

There is no good workaround for the bug - you could try temporarily forcing the WebView's height back to 0 every time the accordion is clicked but that will cause a glitch. Alternatively - if you control your content you could change the JavaScript that runs when the accordion is clicked to tell the WebView that it should shrink back to the previous height:

class MyWebView {
  private int previousHeight = -1;

  @Override
  public void onSizeChanged(int w, int h, int ow, int oh) {
    super.onSizeChanged(w, h, ow, oh);
    previousHeight = h;
  }

  public void accordionClicked() {
    // I'm assuming the accordion is a toggle, so if you click it once
    // it expands, you click it again - it shrinks.
    LayoutParams lp = getLayoutParams();
    if (lp.height == LayoutParams.WRAP_CONTENT)
     lp.height = previousHeight;
    else
     lp.height = LayoutParams.WRAP_CONTENT;
    setLayoutParams(lp);
  }
}

You would then need to use addJavaScriptInterface to expose a way for your JavaScript to call accordionClicked:

class JsInterface {
  private final WebView webView;
  public JsInterface(WebView webView) {
    this.webView = webView;
  }

  @JavascriptInterface
  public void onAccordionClicked() {
    webView.post(new Runnable() {
      @Override
      public void run() {
        webView.accordionClicked();
      }
    });
  }
}

You'd then register this interface in the same place you new up the WebView:

webView.addJavaScriptInterface("jsInterface", new JsInterface(webView);

Finally, call it in your JavaScript:

function accordionClicke() {
  ...
  jsInterface.onAccordionClicked();
}

If your accordion is more complicated you could calculate the height of your content in JavaScript and pass it back to the WebView:

  jsInterface.onAccordionClicked(document.body.clientHeight);

And then use that to set the right height:

  public void accordionClicked(int heightCss) {
    LayoutParams lp = getLayoutParams();
    lp.height = (int) (heightCss * getScale());
    setLayoutParams(lp);

score 0 · Answer 2 · edited May 23 '17 at 12:05

0

use: android:descendantFocusability="blocksDescendants" on the wrapping layout this will prevent the webview from jumping to its start

use: webView.clearView(); mNewsContent.requestLayout(); every time you change the webview size to invalidate the layout, this will remove the empty spacing

for more info see:

edited May 23 '17 at 12:05

Community

1
1

answered Mar 25 '14 at 09:46

Evgeni Roitburg

1,958
21
33

score 0 · Answer 3 · answered Mar 25 '14 at 21:48

0

Actually there is a way. Use this before updating the content:

myWebView.loadUrl("about:blank");

answered Mar 25 '14 at 21:48

hmartinezd

1,188
8
11

SetSize WebView Android

3 Answers3