Android: Disable text selection in a webview - android

I am using a webview to present some formatted stuff in my app. For some interaction (which are specific to certain dom elements) I use javascript and WebView.addJavascriptInterface(). Now, I want to recognize a long touch. Unfortunately, onLongTouch, in Android 2.3 the handles for text selection are displayed.
How can I turn off this text selection without setting the onTouchListener and return true? (Then, the interaction with the "website" doesn't work anymore.

This worked for me
mWebView.setOnLongClickListener(new OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
return true;
}
});
mWebView.setLongClickable(false);
I have not tested, if you don't want the vibration caused by the long click, you can try this:
mWebView.setHapticFeedbackEnabled(false);

Setting webkit css property -webkit-user-select to none would solve the problem.
Example CSS to disable selection:
* {
-webkit-user-select: none;
}

I figured it out!! This is how you can implement your own longtouchlistener. In the function longTouch you can make a call to your javascript interface.
var touching = null;
$('selector').each(function() {
this.addEventListener("touchstart", function(e) {
e.preventDefault();
touching = window.setTimeout(longTouch, 500, true);
}, false);
this.addEventListener("touchend", function(e) {
e.preventDefault();
window.clearTimeout(touching);
}, false);
});
function longTouch(e) {
// do something!
}
This works.

It appears that cut/paste via long press is turned off if you used
articleView.setWebChromeClient(new WebChromeClient(){...})
See https://bugzilla.wikimedia.org/show_bug.cgi?id=31484
So if you are using setChromeClient and you WANT to have long click to start copy/paste, the do the following:
webView.setWebChromeClient(new WebChromeClient(){
[.... other overrides....]
// #Override
// https://bugzilla.wikimedia.org/show_bug.cgi?id=31484
// If you DO NOT want to start selection by long click,
// the remove this function
// (All this is undocumented stuff...)
public void onSelectionStart(WebView view) {
// By default we cancel the selection again, thus disabling
// text selection unless the chrome client supports it.
// view.notifySelectDialogDismissed();
}
});

An alternative solution is to subclass WebView and Override performLongClick as bellow:
public class AdvanceWebView extends WebView {
//Add constructors...
#Override
public boolean performLongClick() {
return true;
}
}

It seems that the only option is to set onTouchListener and write your own code to detect long-click. Then return true if it's a long-click and false otherwise.

For kotlin i found the following to work:
webView.isLongClickable = false

Related

Manually trigger cut/copy/paste in android webview

I'm building a little browser app using android webview and I've been using window.getSelection() in javascript to get the nature of any text selected by the user and show a custom context menu based on the type of the selection i.e. whether it's a range, a carat, whether it's in a contenteditable etc.
This works fine unless the selection is in an iframe, then the browser security measures kick in and prevent me sniffing what has been selected using window.getSelection(). How can I workaround this?
Ideally I need a way to get better information about what was selected from the webview or if that's not possible I need a way to sniff whether the selection occurred in an iframe so I can disable my custom context menu logic and fallback to the default android context menu.
UPDATE/FURTHER CLARIFICATION 07/05/2019:
Seems I wasn't clear enough in my initial description...
My goal is to have a visually and functionally custom menu when selecting content in the webview that can cut/copy/paste as the standard context menu does in any part of the page/iframes etc. e.g.
I realised my original approach using javascript to detect the type of selection and to perform the cut/copy/paste was wrong because it will be blocked by cross origin security in iframes.
What I need is a native android/webview based approach. I've discovered that I can sniff the type of selection in the webview by looking at the items in mode.getMenu() on onActionModeStarted. This will allow me to show the correct buttons in my custom menu UI but I have been unable to manually trigger the same logic that gets called when cut/copy/paste is clicked. I thought I found the solution with webView.performAccessibilityAction(AccessibilityNodeInfo.ACTION_CUT, null); but this doesn't work for some reason so I guess my question really is how can I manually trigger cut/copy/paste on the selected text from webview without using javascript? or any other approach that will allow me to have a custom selection menu with lots of options based on what was selected without hitting the browser security limitations?
Okay I figured out how roughly how to do this.
Step 1) In your activity, override onActionModeStarted and check the menu items available in the default context menu. This gives you a clue as to what the type of selection is and which buttons you will need to show in your custom menu. Also it gives you a reference to the item ID which you can use to later to trigger the action e.g.
systemSelectionMenu = mode.getMenu(); // keep a reference to the menu
MenuItem copyItem = systemSelectionMenu.getItem(0); // fetch any menu items you want
copyActionId = copyItem.getItemId(); // store reference to each item you want to manually trigger
Step 2) Instead of clearing the menu, use setVisible() to hide each menu item you want a custom button for e.g.
copyItem.setVisible(false);
Step 3) In your custom button onclick event you can trigger the copy action using:
myActivity.systemSelectionMenu.performIdentifierAction(myActivity.copyActionId, 0)
You can retrieve iframe's selection only if it has the same origin. Otherwise, you have no chances to track any iframe's events(clicks, touches, key presses, etc.).
const getSelectedText = (win, doc) => {
const isWindowSelectionAvailable = win && typeof win.getSelection != "undefined";
if (isWindowSelectionAvailable) {
return win.getSelection().toString();
}
const hasDocumentSelection = doc && typeof doc.selection != "undefined" && doc.selection.type == "Text";
if (hasDocumentSelection) {
return doc.selection.createRange().text;
}
return '';
}
const doIfTextSelected = (win, doc, cb) => () => {
const selectedText = getSelectedText(win, doc);
if (selectedText) {
cb(selectedText);
}
}
const setupSelectionListener = (win, doc, cb) => {
doc.onmouseup = doIfTextSelected(win, doc, cb);
doc.onkeyup = doIfTextSelected(win, doc, cb);
}
const getIframeWinAndDoc = (iframe) => {
try {
const doc = iframe.contentDocument || iframe.contentWindow.document;
const win = iframe.contentWindow || iframe.contentDocument.defaultView;
return { win, doc };
} catch (e) {
console.error(`${e}`);
return {};
}
}
const callback = console.log;
setupSelectionListener(window, document, callback);
document.querySelectorAll('iframe').forEach(iframe => {
const { win, doc } = getIframeWinAndDoc(iframe, console.log);
// Only for same origin iframes due to https://en.wikipedia.org/wiki/Same-origin_policy
if (win && doc) {
setupSelectionListener(win, doc, callback);
}
})
<h3>Select me</h3>
<div class="container">
<iframe src="https://teimurjan.github.io"></iframe>
</div>
This issue varying from browser to other if it works with internet explorer so it may fall with chrome
Try this
App.util.getSelectedText = function(frameId) {
var frame = Ext.getDom(frameId);
var frameWindow = frame.contentWindow;
var frameDocument = frameWindow.document;
if (frameDocument.getSelection) {
return frameDocument.getSelection();
}
else if (frameDocument.selection) {
return frameDocument.selection.createRange().text;
}
};
Hope it runs fine
Main problem is the window.getSelection() will return selection only for the main context/window. As iframe is the other window and other context, you should call getSelection() from iframe which is "current".

Xamarin Forms Entry Keyboard Stop From Losing Focus

I have an Entry and a Button:
<StackLayout>
<CustomViews:ChatEntryView x:Name="ChatEntry" />
<Button Text="Send" Command="SendCommand"/>
</StackLayout>
What I wanted to achieve here is that when the user starts types something on the Entry control and then presses the button, it should not hide the keyboard (or lose the Entry Focus).
The ChatEntryView here is just actually a custom view that inherits from the Entry control and what I did inside:
1.) Added an Unfocused handler
Unfocused += ChatEntryView_Unfocused;
void ChatEntryView_Unfocused(object sender, FocusEventArgs e)
{
this.Focus();
}
2.) Tried Handling on PropertyChanged
protected override void OnPropertyChanged(string propertyName = null)
{
this.Focus();
base.OnPropertyChanged(propertyName);
}
3.) Tried Handling on PropertyChanging
protected override void OnPropertyChanging(string propertyName = null)
{
this.Focus();
base.OnPropertyChanging(propertyName);
}
But all the three methods doesn't seem to work. I was able to do a work around on IOS by making a custom renderer and it's not very neat (by actually interfacing to the Control.ShouldEndEditing on IOS).
But my problem now is on Android, as I don't exactly know how to do this on Android and there's no Control.ShouldEndEditing (the interface on Android) that I can work with.
What happens by using the handlers above is that, the keyboard for the entry view still loses focus and then immediately gets focuses again which is very odd.
The keyboard pushes down (loses focus) and then pushes up (forced focus).
I know it's too late to anwser this question, but it might be helpful for someone else, I added this code to MainActivity, it might not be a neat solution, but works for me:
private bool _lieAboutCurrentFocus;
public override bool DispatchTouchEvent(MotionEvent ev)
{
var focused = CurrentFocus;
bool customEntryRendererFocused = focused != null && focused.Parent is CustomEntryRenderer_Droid;
_lieAboutCurrentFocus = customEntryRendererFocused;
var result = base.DispatchTouchEvent(ev);
_lieAboutCurrentFocus = false;
return result;
}
public override View CurrentFocus
{
get
{
if (_lieAboutCurrentFocus)
{
return null;
}
return base.CurrentFocus;
}
}

Android onOverrideUrlLoading based on javascript return value

I am working on a hybrid app and trying to return true or false in onOverrideUrlLoading of webview based on returned value from javascript function executed in webview
Example code I have so far.
//Have a boolean variable isExternalDomain;
//Added JavascriptInterface webView.addJavascriptInterface(this, "android");
public boolean onOverrideUrlLoading(final String url) {
WebView.loadUrl("javascript:android.onData('true')");
//I Tried inserting sleep, delay EG: Thread.sleep(200);
//I see the delay but still javascript executes last.
if(isExternalDomain) {
return true;
} else {
return false;
}
}
#JavascriptInterface public void onData(String value)
{
isExternalDomain = true;
}
So the Issue I am having is javascript execution happens after onOverrideUrlLoading completed executing all lines with isExternalDomain as false. I would like to have onOverrideUrlLoading returning true or false based on javascript returned value.
Unfortunately, running JavaScript code from inside onOverrideUrlLoading() isn't possible. You must return from onOverrideUrlLoading() before WebView can do anything else. When you call WebView.loadUrl() from inside onOverrideUrlLoading(), what really happens is an asynchronous task gets posted onto the WebView's message loop. It only gets processed after you leave onOverrideUrlLoading(). Thus, no amount of delay will make WebView to process your request while your code is inside onOverrideUrlLoading().
If you want to prevent navigation from happening based on the decision made by JavaScript code, it's more natural to do that on the JavaScript side by using window.onbeforeunload event handler. If you return non-null value from it, an attempt to navigate away by clicking a link will be cancelled.
Below is a sample of JavaScript code:
window.onbeforeunload = function() {
if (navigationDisallowed()) {
return true; // Prevent navigating away from the page.
} else {
return null; // Allow navigating away.
}
}

Getting "Link text" of the link displayed in WebView

I have Android WebView which displays some links as: Link1TextLink2Text Now I would like to retrieve Link1Text and Link2Text when I long press these links. I have contextMenu implemented in the code and I could successfully get the link urls (http://link1.html, http://link2.html) using HitTestResult getExtra() method but how ccan I get those link texts ?FYI, I require those link texts for implementing "Copy link text" option in the contextMenu.
To get the text of an achor link:
I. Hook a touchstart listener to every web pages in the onPageFinished() callback of WebViewClient via evaluateJavascript. like:
//Javascripts to evaluate in onPageFinished
const w=window;
w.addEventListener('touchstart',wrappedOnDownFunc);
function wrappedOnDownFunc(e){
if(e.touches.length==1){
w._touchtarget = e.touches[0].target;
}
console.log('hey touched something ' +w._touchtarget);
}
note we've saved the touch target.
II. Then implement OnLongClicklisenter for webview. use evaluateJavascript again when you long pressed on a link object:
#Override
public boolean onLongClick(View v) {
WebView.HitTestResult result = ((WebView)v).getHitTestResult();
if (null == result) return false;
int type = result.getType();
switch (type) {
case WebView.HitTestResult.SRC_ANCHOR_TYPE:
if(result.getExtra()!=null){
((WebView)v).evaluateJavascript("window._touchtarget?window._touchtarget.innerText:''", new ValueCallback<String>() {
#Override
public void onReceiveValue(String value) {
System.out.println("hey received link text : "+value);
}
});
}
return true;
}
return false;
}
What's more, we can even choose to select the text of the anchor element! Actually this is one of the options that samsung browser offers when you long-pressed an tag .
To achieve this, we still need that recorded touch target. Besides we need 2 new javascript methods:
function selectTouchtarget(){
var tt = w._touchtarget;
if(tt){
w._touchtarget_href = tt.getAttribute("href");
tt.removeAttribute("href");
var sel = w.getSelection();
var range = document.createRange();
range.selectNodeContents(tt);
sel.removeAllRanges();
sel.addRange(range);
}
}
function restoreTouchtarget(){
var tt = w._touchtarget;
if(tt){
tt.setAttribute("href", w._touchtarget_href);
}
}
Finnaly in the onLongClick listener, instead of just fetch the innerText, we programmatically set the selection, trigger the action menu bar, and restore the removed href attribute of our touch target.
case WebViewmy.HitTestResult.SRC_ANCHOR_TYPE:
if(result.getExtra()!=null){
WebViewmy mWebView = ((WebViewmy)v);
mWebView.evaluateJavascript("selectTouchtarget()", new ValueCallback<String>() {
#Override
public void onReceiveValue(String value) {
/* bring in action mode by a fake click on the programmatically selected text. */
MotionEvent te = MotionEvent.obtain(0,0,KeyEvent.ACTION_DOWN,mWebView.lastX,mWebView.lastY,0);
mWebView.dispatchTouchEvent(te);
te.setAction(KeyEvent.ACTION_UP);
mWebView.dispatchTouchEvent(te);
te.recycle();
//if it's not delayed for a while or the href attribute is not removed, then the above code would click into
// the anchor element instead of select it's text.
/* restore href attribute */
mWebView.postDelayed(() -> mWebView.evaluateJavascript("restoreTouchtarget()", null), 100);
}
});
}
return true;
In my case, I've extended the WebView as WebViewmy to record last touched positions, lastX and lastY, in the onTouchEvent method.
Unfortunately, a clear, official way to do this is not available. Although, there are two APIs (selectText and copySelection) which are pending API council approval, that may help to do this, but they are not available at the moment.

AIR/as3 stage keylistener overriding input textfield

I'm building a mobile AIR app (Android & IOS) with Adobe Flash Builder 4.6 and I'm having this annoying problem.
Because I want to 'catch' the back-key on Android devices I added the following code to my main class:
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDown);
private function keyDown(k:KeyboardEvent):void {
if(k.keyCode == Keyboard.BACK) {
backClicked(); // function handling the back-action, not important
k.preventDefault();
}
Now somewhere else - nested in some classes - I've got a textfield:
TF = new TextField();
TF.type = TextFieldType.INPUT;
But when I set focus on the textfield the soft keyboard does appear, but I can't type a single character. When I disable the keylistener: no problem.
Seems like the listener is overriding my input field. Is there any workaround on this?
I have also implemented the back button functionality for my mobile apps , but i used to register keydown event only when my particular view is activated and removed the registered when view get deactivated.
in <s:view ....... viewActivate ="enableHardwareKeyListeners(event)" viewDeactivate="destroyHardwareKeyListeners(event)">
// add listener only for android device
if (Check for android device) {
NativeApplication.nativeApplication.addEventListener(KeyboardEvent.KEY_DOWN, handleHardwareKeysDown, false, 0);
NativeApplication.nativeApplication.addEventListener(KeyboardEvent.KEY_UP, handleHardwareKeysUp, false, 0);
this.setFocus();
}
private function destroyHardwareKeyListeners(event:ViewNavigatorEvent):void
{
if (NativeApplication.nativeApplication.hasEventListener(KeyboardEvent.KEY_DOWN))
NativeApplication.nativeApplication.removeEventListener(KeyboardEvent.KEY_DOWN, handleHardwareKeysDown);
if (NativeApplication.nativeApplication.hasEventListener(KeyboardEvent.KEY_UP))
NativeApplication.nativeApplication.removeEventListener(KeyboardEvent.KEY_UP, handleHardwareKeysUp);
}
private function handleHardwareKeysDown(e:KeyboardEvent):void
{
if (e.keyCode == Keyboard.BACK) {
e.preventDefault();
// your code
} else {
}
}
private function handleHardwareKeysUp(e:KeyboardEvent):void
{
if (e.keyCode == Keyboard.BACK)
e.preventDefault();
}
May this can help you.

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