Cheok Yan Cheng Cheok Yan Cheng - 10 days ago 5
Android Question

Accurate way to determine the measured height of a view, even before it changed from GONE to VISIBLE

Currently, I have a layout which looks like this. It contains.


  • Title text view, and Price text view, which is visible always.

  • Description Text View, which can be visible or gone, depending expanding or collapsing.



Collapsing (During app startup)



enter image description here

Expanding (When user taps on it)



enter image description here

I want to have some nice animation around it. So, I referred to http://stackoverflow.com/a/13381228/72437

One of the key element, is to know the exact height of Description Text View, even before it is visible.

However, I realize a few type of code. They are't accurate

// v is description text view.
v.measure(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
final int targtetHeight = v.getMeasuredHeight();





// v is description text view.
v.measure(MeasureSpec.makeMeasureSpec(LayoutParams.MATCH_PARENT, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(LayoutParams.WRAP_CONTENT, MeasureSpec.EXACTLY));
final int targtetHeight = v.getMeasuredHeight();


This will return value 32. (The correct measured height suppose to be 92). This is the height for first line of text. This ends up my animation is ended at

enter image description here

May I know, what is the correct way to determine the measured height of a view, even before it changed from GONE to VISIBLE?

My layout code is as followed :

<LinearLayout
android:clickable="true"
android:id="@+id/chart_linear_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:background="@drawable/dummy"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:orientation="horizontal">
<TextView
android:layout_width="0dp"
android:width="0dp"
android:layout_weight="0.6"
android:layout_height="match_parent"
android:gravity="left"
android:textSize="20sp"
android:textColor="#ff000000"
android:text="Summary chart" />
<TextView
android:id="@+id/chart_price_text_view"
android:layout_width="0dp"
android:width="0dp"
android:layout_weight="0.4"
android:layout_height="match_parent"
android:gravity="right"
android:textSize="20sp"
android:textColor="#ffF76D3C"
android:text="$2.99" />

</LinearLayout>
<TextView
android:visibility="gone"
android:id="@+id/chart_description_text_view"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginBottom="10dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/currency_exchange_description"
android:textColor="#ff626262"
android:textSize="15sp" />
</LinearLayout>

nmw nmw
Answer

Your 2nd code snippet is almost correct, but you need to specify pixel sizes - not FILL_PARENT/MATCH_PARENT. This should work:

v.measure(MeasureSpec.makeMeasureSpec(parentView.getWidth(), MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(MAX_HEIGHT, MeasureSpec.AT_MOST));
final int targetHeight = v.getMeasuredHeight();

You'll need to have a reference to the ViewGroup that v is a child of to get its width, and define MAX_HEIGHT (or perhaps use the parent View's height?).

Also, you should change the height parameters of the two TextViews that are within the horizontal LinearLayout to wrap_content, as using match_parent here may cause problems. The LinearLayout is set to wrap_content, but the two children don't specify a height.