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Commit 322171b3 authored by Erik's avatar Erik
Browse files

Adds a way to scroll to a position in a given duration 

Adds a method to AbsListView to allow for a smooth scroll to an
offset position with an app defined duration.

Change-Id: I8cd690597cda078b25bce9aeba683be030d6b155
parent 0a9b54e8

api/current.xml

+17 −0
Original line number Diff line number Diff line
@@ -225530,6 +225530,23 @@ 
</parameter>

<parameter name="offset" type="int">

</parameter>

<parameter name="duration" type="int">

</parameter>

</method>

<method name="smoothScrollToPositionFromTop"

 return="void"

 abstract="false"

 native="false"

 synchronized="false"

 static="false"

 final="false"

 deprecated="not deprecated"

 visibility="public"

>

<parameter name="position" type="int">

</parameter>

<parameter name="offset" type="int">

</parameter>

</method>

<method name="verifyDrawable"

 return="boolean"

core/java/android/widget/AbsListView.java

+27 −4
Original line number Diff line number Diff line
@@ -3050,6 +3050,10 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te 
        }



        void startWithOffset(int position, int offset) {

            startWithOffset(position, offset, SCROLL_DURATION);

        }



        void startWithOffset(int position, int offset, int duration) {

            mTargetPos = position;

            mOffsetFromTop = offset;

            mBoundPos = INVALID_POSITION;
@@ -3068,14 +3072,14 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te 
            } else {

                // On-screen, just scroll.

                final int targetTop = getChildAt(position - firstPos).getTop();

                smoothScrollBy(targetTop - offset, SCROLL_DURATION);

                smoothScrollBy(targetTop - offset, duration);

                return;

            }



            // Estimate how many screens we should travel

            final float screenTravelCount = (float) viewTravelCount / childCount;

            mScrollDuration = screenTravelCount < 1 ? (int) (screenTravelCount * SCROLL_DURATION) :

                    (int) (SCROLL_DURATION / screenTravelCount);

            mScrollDuration = screenTravelCount < 1 ? (int) (screenTravelCount * duration) :

                    (int) (duration / screenTravelCount);

            mLastSeenPos = INVALID_POSITION;



            post(this);
@@ -3285,6 +3289,25 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te 
        mPositionScroller.start(position);

    }



    /**

     * Smoothly scroll to the specified adapter position. The view will scroll

     * such that the indicated position is displayed <code>offset</code> pixels from

     * the top edge of the view. If this is impossible, (e.g. the offset would scroll

     * the first or last item beyond the boundaries of the list) it will get as close

     * as possible. The scroll will take <code>duration</code> milliseconds to complete.

     *

     * @param position Position to scroll to

     * @param offset Desired distance in pixels of <code>position</code> from the top

     *               of the view when scrolling is finished

     * @param duration Number of milliseconds to use for the scroll

     */

    public void smoothScrollToPositionFromTop(int position, int offset, int duration) {

        if (mPositionScroller == null) {

            mPositionScroller = new PositionScroller();

        }

        mPositionScroller.startWithOffset(position, offset, duration);

    }



    /**

     * Smoothly scroll to the specified adapter position. The view will scroll

     * such that the indicated position is displayed <code>offset</code> pixels from