What does String.valueOf(View) returns?

Question

I was using some Logs to debug some issues in my app, and when I used String.valueOf(view) in a onClick(View view).

I logged Log.d("Values", "HomeFragment: onClick. view = " + String.valueOf(view));

The result of the Log was: D/Values: HomeFragment: onClick. view = android.widget.RelativeLayout{cca8bb V.E...C.. ...P.... 0,512-1080,1024 #7f0c0079 app:id/button_2}

I would like to know what that means. I have been trying to get the information from the Android Developers reference, but the closest was the deffinition of valueOf (Object value) that is too generic.

Where should I go to get the information returned for a specific object by String.valueOf()?

score 4 · Accepted Answer · answered Feb 27 '16 at 12:10

String.valueOf(object) just calls the toString method of the object. If you decompile the View class, you get:

// toString method of the View class
public String toString() {
    StringBuilder out = new StringBuilder(128);
    out.append(getClass().getName());
    out.append('{');
    out.append(Integer.toHexString(System.identityHashCode(this)));
    out.append(' ');
    switch (mViewFlags&VISIBILITY_MASK) {
        case VISIBLE: out.append('V'); break;
        case INVISIBLE: out.append('I'); break;
        case GONE: out.append('G'); break;
        default: out.append('.'); break;
    }
    out.append((mViewFlags&FOCUSABLE_MASK) == FOCUSABLE ? 'F' : '.');
    out.append((mViewFlags&ENABLED_MASK) == ENABLED ? 'E' : '.');
    out.append((mViewFlags&DRAW_MASK) == WILL_NOT_DRAW ? '.' : 'D');
    out.append((mViewFlags&SCROLLBARS_HORIZONTAL) != 0 ? 'H' : '.');
    out.append((mViewFlags&SCROLLBARS_VERTICAL) != 0 ? 'V' : '.');
    out.append((mViewFlags&CLICKABLE) != 0 ? 'C' : '.');
    out.append((mViewFlags&LONG_CLICKABLE) != 0 ? 'L' : '.');
    out.append((mViewFlags&CONTEXT_CLICKABLE) != 0 ? 'X' : '.');
    out.append(' ');
    out.append((mPrivateFlags&PFLAG_IS_ROOT_NAMESPACE) != 0 ? 'R' : '.');
    out.append((mPrivateFlags&PFLAG_FOCUSED) != 0 ? 'F' : '.');
    out.append((mPrivateFlags&PFLAG_SELECTED) != 0 ? 'S' : '.');
    if ((mPrivateFlags&PFLAG_PREPRESSED) != 0) {
        out.append('p');
    } else {
        out.append((mPrivateFlags&PFLAG_PRESSED) != 0 ? 'P' : '.');
    }
    out.append((mPrivateFlags&PFLAG_HOVERED) != 0 ? 'H' : '.');
    out.append((mPrivateFlags&PFLAG_ACTIVATED) != 0 ? 'A' : '.');
    out.append((mPrivateFlags&PFLAG_INVALIDATED) != 0 ? 'I' : '.');
    out.append((mPrivateFlags&PFLAG_DIRTY_MASK) != 0 ? 'D' : '.');
    out.append(' ');
    out.append(mLeft);
    out.append(',');
    out.append(mTop);
    out.append('-');
    out.append(mRight);
    out.append(',');
    out.append(mBottom);
    final int id = getId();
    if (id != NO_ID) {
        out.append(" #");
        out.append(Integer.toHexString(id));
        final Resources r = mResources;
        if (Resources.resourceHasPackage(id) && r != null) {
            try {
                String pkgname;
                switch (id&0xff000000) {
                    case 0x7f000000:
                        pkgname="app";
                        break;
                    case 0x01000000:
                        pkgname="android";
                        break;
                    default:
                        pkgname = r.getResourcePackageName(id);
                        break;
                }
                String typename = r.getResourceTypeName(id);
                String entryname = r.getResourceEntryName(id);
                out.append(" ");
                out.append(pkgname);
                out.append(":");
                out.append(typename);
                out.append("/");
                out.append(entryname);
            } catch (Resources.NotFoundException e) {
            }
        }
    }
    out.append("}");
    return out.toString();
}

So, in your example:

android.widget.RelativeLayout = class name
cca8bb = identity hashcode (in hex)
V.E...C.. ...P.... = View is visible, mask enabled, clickable, button pressed
0,512-1080,1024 = left, top - right, bottom distancs in pixels from the edges of this view's parent to the edges of this view.
#7f0c0079 = id of the view, in hex
app:id/button_2 = the string id of this view (in your layout file)

Thank you very much! Actually I went to the View source code, but at `toString` method I just found: `public String toString() { throw new RuntimeException("Stub!"); }` Probably it is somewhere else that I cannot find in the code of View. Thanks!! — Daniel Reina, Feb 27 '16 at 12:20

What does String.valueOf(View) returns?

1 Answers1