Find All Views with Tag

Find all views with tag?

Here you go:

private static ArrayList<View> getViewsByTag(ViewGroup root, String tag){
    ArrayList<View> views = new ArrayList<View>();
    final int childCount = root.getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = root.getChildAt(i);
        if (child instanceof ViewGroup) {
            views.addAll(getViewsByTag((ViewGroup) child, tag));
        }

        final Object tagObj = child.getTag();
        if (tagObj != null && tagObj.equals(tag)) {
            views.add(child);
        }

    }
    return views;
}

I've already answered it here :Android - how to find multiple views with common attribute

How to find list of View(s) that has a specific Tag (attribute)

You shouldnt expect an array of views from this method, since the method signature itself tells that it will return a single view.

public final View findViewWithTag (Object tag) 

However, what you may do is to get your layout as ViewGroup and then iterate through all the child views to find out your desired view by doing a look-up on their tag. For example:

/**
 * Get all the views which matches the given Tag recursively
 * @param root parent view. for e.g. Layouts
 * @param tag tag to look for
 * @return List of views
 */
public static List<View> findViewWithTagRecursively(ViewGroup root, Object tag){
    List<View> allViews = new ArrayList<View>();

    final int childCount = root.getChildCount();
    for(int i=0; i<childCount; i++){
        final View childView = root.getChildAt(i);

        if(childView instanceof ViewGroup){
          allViews.addAll(findViewWithTagRecursively((ViewGroup)childView, tag));
        }
        else{
            final Object tagView = childView.getTag();
            if(tagView != null && tagView.equals(tag))
                allViews.add(childView);
        }
    }

    return allViews;
}

Android - how to find multiple views with common attribute

I've finally wrote this method (Updated thanks to @SuitUp (corrected username)):

private static ArrayList<View> getViewsByTag(ViewGroup root, String tag){
    ArrayList<View> views = new ArrayList<View>();
    final int childCount = root.getChildCount();
    for (int i = 0; i < childCount; i++) {
        final View child = root.getChildAt(i);
        if (child instanceof ViewGroup) {
            views.addAll(getViewsByTag((ViewGroup) child, tag));
        } 

        final Object tagObj = child.getTag();
        if (tagObj != null && tagObj.equals(tag)) {
            views.add(child);
        }

    }
    return views;
}

It will return all views that have android:tag="TAG_NAME" attribute. Enjoy ;)

Android findViewWithTag for views with multiple tags

findViewWithTag(tag) returns the View with the default tag set by setTag(tag) as compared using tag.equals(getTag()).

Android: Getting list of views by tag and changing specific button

instanceof

I am not an Android programmer, but it looks like your Question is a basic Java question. Are you saying:

I have an object being returned as the superclass Object. But I know in fact that the object is an instance of the Button class. How can I refer to it as a Button specifically rather than as Object generally?

If so, simply cast the object. Going from the more general super-type to the more specific type is downcasting.

Object o = gridcells.get(0) ;
Button b = ( Button ) o ;

Or combine:

Button b = ( Button ) gridcells.get(0) ;

If not quite sure, do a check with the special operator instanceof.

if( gridcells.get(0) instanceof Button ) {
    Button b = ( Button ) gridcells.get(0) ;
}

If you are doing much casting in your code, you likely have a design problem. Usually that stems from not understanding the basics of Object-Oriented Programming. But occasionally some casting is in order and cannot be avoided.

See this similar Question for more discussion.

If I am misunderstanding the Question, you may need to re-write your Question.

---

Related Topics