Horizontal scroll view expanding when views added programmatically

Question

I'm having problems when adding views programmatically to a horizontal scroll view. I have a horizontal scroll view with a dotted background and have given the linear layouts around it clear colour backgrounds to aid with understanding.

This is what the view looks like prior

Then I add a view to the scroll view after a drag and drop event:

MemoNodeView mn = new MemoNodeView(this);
mn.setMemo(m);
int time = (int) Math.round(pixelsPerMilliSecond()*m.getTimeLength());
mn.setMemoSize(time, timelineHeight);
timeline.addView(mn, new ViewGroup.MarginLayoutParams(time, timelineHeight));

This leads to the view expanding in size vertically:

I attempted to fix this by re-setting the layout params of the linear layout inside the scroll view based on the height it was supposed to have:

ViewGroup.LayoutParams p = timeline.getLayoutParams();
p.height = timelineHeight;
timeline.setLayoutParams(p);

Leading to this situation where the scroll view is still expanded but the content is the right size:

I then tried to resize the scroll view itself so that the size matched what it was supposed to:

ViewGroup.LayoutParams p2 = timelineScrollView.getLayoutParams();
p2.height = timelineHeight;
timelineScrollView.setLayoutParams(p2);

which gave:

Leaving the size of the scroll view correct, but the size of the other views shrunken and slightly in the wrong position. What I want is for the scroll view to remain the same as in the first image and for nothing to move around. It may be something basic, but I cant for the life of me figure out what I'm doing wrong to give this behaviour.

The xml for the area is as follows (note that the colours/ text views are placeholders used to try and help make the issue stand out visually):

`<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/black_frame"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:background="#ffffff" >

        <TextView
            android:id="@+id/textView1"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="Small Text" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/LinearLayout1"
        android:layout_width="match_parent"
        android:layout_height="0dip"
        android:layout_weight="3"
        android:orientation="vertical"
        android:paddingLeft="@dimen/toggle_draw_padding"
        android:paddingRight="@dimen/toggle_draw_padding" >


        <HorizontalScrollView
            android:id="@+id/horizontal_scroll_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@drawable/timeline_dots_bitmap" 
            android:fillViewport="true">

            <LinearLayout
                android:id="@+id/timeline_view"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:orientation="horizontal"
                android:background="#F0AA4444" >
            </LinearLayout>
        </HorizontalScrollView>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:background="#ffffff" >

        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="Small Text" />
    </LinearLayout>
</LinearLayout>`

Any ideas as to what I am doing wrong here?

Answer 1

I found out what was causing the issue. I'll post here in case anyone else has a similar issue and it is also driving them mental...

The linear layouts that had the white backgrounds had the layout_height="match_parent" which gave the weird behaviour when other views were added. Changing the two layouts to layout_height="0dip" solves the issue. As shown below:

`

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dip"
        android:layout_weight="1"
        android:background="#ffffff" >

        <TextView
            android:id="@+id/textView1"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="Small Text" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/LinearLayout1"
        android:layout_width="match_parent"
        android:layout_height="0dip"
        android:layout_weight="3"
        android:orientation="vertical"
        android:paddingLeft="@dimen/toggle_draw_padding"
        android:paddingRight="@dimen/toggle_draw_padding" 
        >


        <HorizontalScrollView
            android:id="@+id/horizontal_scroll_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@drawable/timeline_dots_bitmap" 
            android:fillViewport="true"
            android:layout_margin="0dip"
            android:padding="0dip">

            <LinearLayout
                android:id="@+id/timeline_view"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:orientation="horizontal"
                android:background="#F0AA4444" 
                android:layout_margin="0dip"
                android:padding="0dip">
            </LinearLayout>
        </HorizontalScrollView>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dip"
        android:layout_weight="1"
        android:background="#ffffff" >

        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="Small Text" />
    </LinearLayout>
</LinearLayout>`

I hope that this can help anyone who somehow makes the same mistake I did.