getMeasuredHeight() is wrong? about flexbox-layout HOT 8 CLOSED

The values between getMeasuredHeight/Width and getHeight/Width don't have to be same as in explained in the documentation.

Also I believe you don't have to use the getMeasuredHeight/Width method in your app because it's used for the layout pass (done within the library).
So please use getHeight instead. If there is an issue in that method, please report an issue.

from flexbox-layout.

Hello,

To clarify, I said that getHeight() and getMeasuredHeight() were returning the same value when they should not have been, not that they should have been returning the same value. This is the issue I was trying to report. If the FlexboxLayout is set to wrap_content in a RelativeLayout that is set to a fixed height, and the FlexboxLayout contains enough items to exceed the fixed height of the RelativeLayout, it is my understanding that getMeasuredHeight() and getHeight() should return different values, but they are not.

My app needs to get the measured height of the FlexboxLayout in order to move/resize some sibling views, since cyclic dependencies would arise if attempting to use only RelativeLayout layout parameters.

To work around this issue, I have resorted to measuring the size of each line and dividers and summing them up, but a fix for getMeasuredHeight() would be better.

from flexbox-layout.

Hi,

If the FlexboxLayout is set to wrap_content in a RelativeLayout that is set to a fixed height, and the FlexboxLayout contains enough items to exceed the fixed height of the RelativeLayout, it is my understanding that getMeasuredHeight() and getHeight() should return different values,

Actually this is not correct.
Even if the length of the FlexboxLayout is set to wrap_content and the parent RelativeLayout has a fixed height, it doesn't mean the getMesuredHeight and getHeight should return the different values.
Again, I think getMeasuredHeight is not meant to be used for outside of the view itself.
Please consider another approach.

from flexbox-layout.

Sorry to disagree, but from the documentation you linked:

The first pair is known as measured width and measured height. These dimensions define how big a view wants to be within its parent (see Layout for more details.) The measured dimensions can be obtained by calling getMeasuredWidth() and getMeasuredHeight().

A natural follow up question is, what exactly does "wants to be" mean? The answer is found by following the link to the Layout section. In the case of layout_height being set to wrap_content:

WRAP_CONTENT, which means that the view wants to be just big enough to enclose its content (plus padding).

(emphasis mine)

So according to this, if the content would make its own container bigger than its container's container (which in my case has a fixed height), getMeasuredHeight() should return a number bigger than the number returned by getHeight().

Granted, the documentation for getMeasuredHeightAndState(), which getMeasuredHeight() references, does say:

This should be used during measurement and layout calculations only. Use getHeight() to see how wide a view is after layout.

In my specific case I am actually trying to get the measured height of the view during layout (in OnGlobalLayoutListener.OnGlobalLayout()). The above documentation seems to indicate that getMeasuredHeight() should return the height the view wants to be regardless of its container's size at this point in time. Many stack overflow answers recommend this method for getting this measurement, for any view in general. If this is wrong as you say, then I suppose that the View documentation needs updating, but I find it more likely that FlexboxLayout has this implemented incorrectly. Please reconsider your closing of this issue.

from flexbox-layout.

Ok so could you share the example xml of this?

FlexboxLayout is set to wrap_content in a RelativeLayout that is set to a fixed height, and the FlexboxLayout contains enough items to exceed the fixed height of the RelativeLayout

I'll check if it's not the intended behavior.

from flexbox-layout.

Sure thing, and thanks for your consideration.

A direct paste of my layout xml is difficult since the relevant sections are broken up into 2 xml files, the RelativeLayout is actually a custom view in my case, and its contents are dynamically inflated. So instead I'll just create an example here with similar parameters:

<RelativeLayout
    android:layout_width="200dp"
    android:layout_height="200dp">
    <com.google.android.flexbox.FlexboxLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:flexWrap="wrap"
        app:alignItems="flex_start"
        app:alignContent="center"
        app:showDivider="middle"
        app:dividerDrawable="@android:drawable/btn_dialog">
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
    </com.google.android.flexbox.FlexboxLayout>
</RelativeLayout>

Now in onCreate() if you do:

flexBox.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        Log.d("flex", "measured height = " + flexBox.getMeasuredHeight());
        Log.d("flex", "height = " + flexBox.getHeight());
    }
});

I think you would see the same value logged twice.

from flexbox-layout.

Thanks for pasting the xml.

Checked that it was an intended behavior that the getMeasuredHeight and getHeight return the same value.
Because the value set to the measured height takes the spec parameters imposed by its parent (passed as widthMeasureSpec and heightMeasureSpec from the parent) into account as well as the value for getHeight.
If you replace the FlexboxLayout with LinearLayout, you can also check that getMeasuredHeight and getHeight return the same value.

(I tried this xml)

<RelativeLayout android:layout_width="200dp"
    android:layout_height="200dp"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <LinearLayout
        android:id="@+id/flexbox_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:divider="@android:drawable/btn_dialog"
        android:showDividers="middle"
        android:orientation="vertical"
        >
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/sym_def_app_icon"/>
    </LinearLayout>
</RelativeLayout>

from flexbox-layout.

Ah, then I suppose it is the View documentation that needs updating. I'm sorry I didn't simply check the behavior of other built-in Android ViewGroups before opening this issue. Then all this back and forth could have been avoided. Thank you very much for looking into it.

from flexbox-layout.