enable disable zoom in Android WebView

Question

There are some methods in WebSettings related to zoom    WebSettings setSupportZoom WebSettings setBuiltInZoomControls   I noticed they work differently on some devices  For example  on my Galaxy S pinch to zoom is enabled by default  but on LG P500 it is disabled  And now I don t know how to enable ONLY pinch to zoom  but hide zooming buttons    On P500 when I call setBuiltInZoomControls true  I get both these variants working  multitouch and buttons    How to enable multitouch zoom and disable zooming buttons on devices such an LG P500   Also  I know the same problems are on HTC devices   UPDATE  Here is almost full code for the solution   if  ev getAction      MotionEvent ACTION DOWN            ev getAction      MotionEvent ACTION POINTER DOWN            ev getAction      MotionEvent ACTION POINTER 1 DOWN            ev getAction      MotionEvent ACTION POINTER 2 DOWN            ev getAction      MotionEvent ACTION POINTER 3 DOWN        if  multiTouchZoom  amp  amp   buttonsZoom            if  getPointerCount ev   gt  1                getSettings   setBuiltInZoomControls true               getSettings   setSupportZoom true             else               getSettings   setBuiltInZoomControls false               getSettings   setSupportZoom false                      if   multiTouchZoom  amp  amp  buttonsZoom        if  getPointerCount ev   gt  1            return true            This code is in my onTouchEvent overridden method of the WebView

User · Accepted Answer

I ve looked at the source code for WebView and I concluded that there is no elegant way to accomplish what you are asking   What I ended up doing was subclassing WebView and overriding OnTouchEvent  In OnTouchEvent for ACTION DOWN  I check how many pointers there are using MotionEvent getPointerCount    If there is more than one pointer  I call setSupportZoom true   otherwise I call setSupportZoom false    I then call the super OnTouchEvent     This will effectively disable zooming when scrolling  thus disabling the zoom controls  and enable zooming when the user is about to pinch zoom   Not a nice way of doing it  but it has worked well for me so far   Note that getPointerCount   was introduced in 2 1 so you ll have to do some extra stuff if you support 1 6

User · Answer

The solution you posted seems to work in stopping the zoom controls from appearing when the user drags  however there are situations where a user will pinch zoom and the zoom controls will appear  I ve noticed that there are 2 ways that the webview will accept pinch zooming  and only one of them causes the zoom controls to appear despite your code   User Pinch Zooms and controls appear   ACTION DOWN getSettings   setBuiltInZoomControls false   getSettings   setSupportZoom false   ACTION POINTER 2 DOWN getSettings   setBuiltInZoomControls true   getSettings   setSupportZoom true   ACTION MOVE  Repeat several times  as the user moves their fingers  ACTION POINTER 2 UP ACTION UP   User Pinch Zoom and Controls don t appear   ACTION DOWN getSettings   setBuiltInZoomControls false   getSettings   setSupportZoom false   ACTION POINTER 2 DOWN getSettings   setBuiltInZoomControls true   getSettings   setSupportZoom true   ACTION MOVE  Repeat several times  as the user moves their fingers  ACTION POINTER 1 UP ACTION POINTER UP ACTION UP   Can you shed more light on your solution

User · Answer

Ive modifiet Lukas Knuth s solution a little   1  There s no need to subclass the webview    2  the code will crash during bytecode verification on some Android 1 6 devices if you don t put nonexistant methods in seperate classes  3  Zoom controls will still appear if the user scrolls up down a page  I simply set the zoom controller container to visibility GONE    wv getSettings   setSupportZoom true     wv getSettings   setBuiltInZoomControls true     if  android os Build VERSION SDK INT  gt   android os Build VERSION CODES HONEYCOMB           Use the API 11  calls to disable the controls        Use a seperate class to obtain 1 6 compatibility     new Runnable           public void run             wv getSettings   setDisplayZoomControls false                 run        else       final ZoomButtonsController zoom controll            ZoomButtonsController  wv getClass   getMethod  getZoomButtonsController   invoke wv  null       zoom controll getContainer   setVisibility View GONE

User · Answer

Lukas Knuth have good solution  but on android 4 0 4 on Samsung Galaxy SII I still look zoom controls  And I solve it via   if  zoom controll  null  amp  amp  zoom controll getZoomControls    null          Hide the controlls AFTER they where made visible by the default implementation     zoom controll getZoomControls   setVisibility View GONE       instead of   if  zoom controll    null         Hide the controlls AFTER they where made visible by the default implementation     zoom controll setVisible false

User · Answer

hey there for anyone who might be looking for solution like this    i had issue with scaling inside WebView so best way to do is in your java class where you set all for webView put this two line of code   webViewSearch is name of my webView -- webViewSearch    WebView  findViewById R id id webview search        force WebView to show content not zoomed---------------------------------------------------------     webViewSearch getSettings   setLoadWithOverviewMode true       webViewSearch getSettings   setUseWideViewPort true

User · Answer

On API    11  you can use   wv getSettings   setBuiltInZoomControls true   wv getSettings   setDisplayZoomControls false     As per the SDK   public void setDisplayZoomControls  boolean enabled        Since  API Level   11      Sets whether the on screen zoom buttons are used  A combination of   built in zoom controls enabled and on screen zoom controls disabled   allows for pinch to zoom to work without the on screen controls

User · Answer

Improved Lukas Knuth s version   public class TweakedWebView extends WebView        private ZoomButtonsController zoomButtons       public TweakedWebView Context context            super context           init               public TweakedWebView Context context  AttributeSet attrs            super context  attrs           init               public TweakedWebView Context context  AttributeSet attrs  int defStyle            super context  attrs  defStyle           init               private void init             getSettings   setBuiltInZoomControls true           if  Build VERSION SDK INT  gt   Build VERSION CODES HONEYCOMB                getSettings   setDisplayZoomControls false             else               try                   Method method   getClass                            getMethod  getZoomButtonsController                    zoomButtons    ZoomButtonsController  method invoke this                 catch  Exception e                       pass                                     Override     public boolean onTouchEvent MotionEvent ev            boolean result   super onTouchEvent ev           if  zoomButtons    null                zoomButtons setVisible false               zoomButtons getZoomControls   setVisibility View GONE                     return result

User · Answer

We had the same problem while working on an Android application for a customer and I managed to  hack  around this restriction   I took a look at the Android Source code for the WebView class and spotted a updateZoomButtonsEnabled  -method which was working with an ZoomButtonsController-object to enable and disable the zoom controls depending on the current scale of the browser   I searched for a method to return the ZoomButtonsController-instance and found the getZoomButtonsController  -method  that returned this very instance   Although the method is declared public  it is not documented in the WebView-documentation and Eclipse couldn t find it either  So  I tried some reflection on that and created my own WebView-subclass to override the onTouchEvent  -method  which triggered the controls   public class NoZoomControllWebView extends WebView        private ZoomButtonsController zoom controll   null       public NoZoomControllWebView Context context            super context           disableControls               public NoZoomControllWebView Context context  AttributeSet attrs  int defStyle            super context  attrs  defStyle           disableControls               public NoZoomControllWebView Context context  AttributeSet attrs            super context  attrs           disableControls                          Disable the controls             private void disableControls            if  android os Build VERSION SDK INT  gt   android os Build VERSION CODES HONEYCOMB                   Use the API 11  calls to disable the controls             this getSettings   setBuiltInZoomControls true               this getSettings   setDisplayZoomControls false             else                  Use the reflection magic to make it work on earlier APIs             getControlls                                    This is where the magic happens  D             private void getControlls             try               Class webview   Class forName  android webkit WebView                Method method   webview getMethod  getZoomButtonsController                zoom controll    ZoomButtonsController  method invoke this  null             catch  Exception e                e printStackTrace                          Override     public boolean onTouchEvent MotionEvent ev            super onTouchEvent ev           if  zoom controll    null                  Hide the controlls AFTER they where made visible by the default implementation              zoom controll setVisible false                     return true            You might want to remove the unnecessary constructors and react on probably on the exceptions   Although this looks hacky and unreliable  it works back to API Level 4  Android 1 6      As  jayellos pointed out in the comments  the private getZoomButtonsController  -method is no longer existing on Android 4 0 4 and later   However  it doesn t need to  Using conditional execution  we can check if we re on a device with API Level 11  and use the exposed functionality  see  Yuttadhammo answer  to hide the controls   I updated the example code above to do exactly that

[android] enable/disable zoom in Android WebView

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