Refactoring fast scroller.
- Fixing issue with fast scroller not fitting name width.
- Refactoring fast scrolling/scroll bar code out of base recycler view
- Adding animations to fast scroller to match design
- Smooth scrolling when jumping between app rows
- Fixing issue with fast scroller jumping when you first pick it up
- Fixing issue with wrong background paddings being used
Bug: 21874346
Bug: 22031923
Change-Id: I9f011b1f375751f437604b900e95a2942d3f4601
diff --git a/src/com/android/launcher3/BaseRecyclerView.java b/src/com/android/launcher3/BaseRecyclerView.java
index 140c28c..0fae427 100644
--- a/src/com/android/launcher3/BaseRecyclerView.java
+++ b/src/com/android/launcher3/BaseRecyclerView.java
@@ -16,24 +16,15 @@
package com.android.launcher3;
-import android.animation.Animator;
-import android.animation.AnimatorListenerAdapter;
-import android.animation.ObjectAnimator;
import android.content.Context;
-import android.content.res.Resources;
import android.graphics.Canvas;
-import android.graphics.Color;
-import android.graphics.Paint;
import android.graphics.Rect;
-import android.graphics.drawable.Drawable;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;
import android.view.MotionEvent;
-import android.view.View;
-import android.view.ViewConfiguration;
-
import com.android.launcher3.util.Thunk;
+
/**
* A base {@link RecyclerView}, which does the following:
* <ul>
@@ -41,7 +32,7 @@
* <li> Enable fast scroller.
* </ul>
*/
-public class BaseRecyclerView extends RecyclerView
+public abstract class BaseRecyclerView extends RecyclerView
implements RecyclerView.OnItemTouchListener {
private static final int SCROLL_DELTA_THRESHOLD_DP = 4;
@@ -50,14 +41,8 @@
@Thunk int mDy = 0;
private float mDeltaThreshold;
- //
- // Keeps track of variables required for the second function of this class: fast scroller.
- //
-
- private static final float FAST_SCROLL_OVERLAY_Y_OFFSET_FACTOR = 1.5f;
-
/**
- * The current scroll state of the recycler view. We use this in updateVerticalScrollbarBounds()
+ * The current scroll state of the recycler view. We use this in onUpdateScrollbar()
* and scrollToPositionAtProgress() to determine the scroll position of the recycler view so
* that we can calculate what the scroll bar looks like, and where to jump to from the fast
* scroller.
@@ -70,27 +55,12 @@
// The height of a given row (they are currently all the same height)
public int rowHeight;
}
- // Should be maintained inside overriden method #updateVerticalScrollbarBounds
- public ScrollPositionState scrollPosState = new ScrollPositionState();
- public Rect verticalScrollbarBounds = new Rect();
- private boolean mDraggingFastScroller;
-
- private Drawable mScrollbar;
- private Drawable mFastScrollerBg;
- private Rect mTmpFastScrollerInvalidateRect = new Rect();
- private Rect mFastScrollerBounds = new Rect();
-
- private String mFastScrollSectionName;
- private Paint mFastScrollTextPaint;
- private Rect mFastScrollTextBounds = new Rect();
- private float mFastScrollAlpha;
+ protected BaseRecyclerViewFastScrollBar mScrollbar;
private int mDownX;
private int mDownY;
private int mLastY;
- private int mScrollbarWidth;
- private int mScrollbarInset;
protected Rect mBackgroundPadding = new Rect();
public BaseRecyclerView(Context context) {
@@ -104,25 +74,10 @@
public BaseRecyclerView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
mDeltaThreshold = getResources().getDisplayMetrics().density * SCROLL_DELTA_THRESHOLD_DP;
+ mScrollbar = new BaseRecyclerViewFastScrollBar(this, getResources());
ScrollListener listener = new ScrollListener();
setOnScrollListener(listener);
-
- Resources res = context.getResources();
- int fastScrollerSize = res.getDimensionPixelSize(R.dimen.all_apps_fast_scroll_popup_size);
- mScrollbar = res.getDrawable(R.drawable.all_apps_scrollbar_thumb);
- mFastScrollerBg = res.getDrawable(R.drawable.all_apps_fastscroll_bg);
- mFastScrollerBg.setBounds(0, 0, fastScrollerSize, fastScrollerSize);
- mFastScrollTextPaint = new Paint();
- mFastScrollTextPaint.setColor(Color.WHITE);
- mFastScrollTextPaint.setAntiAlias(true);
- mFastScrollTextPaint.setTextSize(res.getDimensionPixelSize(
- R.dimen.all_apps_fast_scroll_text_size));
- mScrollbarWidth = res.getDimensionPixelSize(R.dimen.all_apps_fast_scroll_bar_width);
- mScrollbarInset =
- res.getDimensionPixelSize(R.dimen.all_apps_fast_scroll_scrubber_touch_inset);
- setFastScrollerAlpha(mFastScrollAlpha);
- setOverScrollMode(View.OVER_SCROLL_NEVER);
}
private class ScrollListener extends OnScrollListener {
@@ -133,6 +88,10 @@
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
mDy = dy;
+
+ // TODO(winsonc): If we want to animate the section heads while scrolling, we can
+ // initiate that here if the recycler view scroll state is not
+ // RecyclerView.SCROLL_STATE_IDLE.
}
}
@@ -161,8 +120,6 @@
* it is already showing).
*/
private boolean handleTouchEvent(MotionEvent ev) {
- ViewConfiguration config = ViewConfiguration.get(getContext());
-
int action = ev.getAction();
int x = (int) ev.getX();
int y = (int) ev.getY();
@@ -174,41 +131,19 @@
if (shouldStopScroll(ev)) {
stopScroll();
}
+ mScrollbar.handleTouchEvent(ev, mDownX, mDownY, mLastY);
break;
case MotionEvent.ACTION_MOVE:
- // Check if we are scrolling
- if (!mDraggingFastScroller && isPointNearScrollbar(mDownX, mDownY) &&
- Math.abs(y - mDownY) > config.getScaledTouchSlop()) {
- getParent().requestDisallowInterceptTouchEvent(true);
- mDraggingFastScroller = true;
- animateFastScrollerVisibility(true);
- }
- if (mDraggingFastScroller) {
- mLastY = y;
-
- // Scroll to the right position, and update the section name
- int top = getPaddingTop() + (mFastScrollerBg.getBounds().height() / 2);
- int bottom = getHeight() - getPaddingBottom() -
- (mFastScrollerBg.getBounds().height() / 2);
- float boundedY = (float) Math.max(top, Math.min(bottom, y));
- mFastScrollSectionName = scrollToPositionAtProgress((boundedY - top) /
- (bottom - top));
-
- // Combine the old and new fast scroller bounds to create the full invalidate
- // rect
- mTmpFastScrollerInvalidateRect.set(mFastScrollerBounds);
- updateFastScrollerBounds();
- mTmpFastScrollerInvalidateRect.union(mFastScrollerBounds);
- invalidateFastScroller(mTmpFastScrollerInvalidateRect);
- }
+ mLastY = y;
+ mScrollbar.handleTouchEvent(ev, mDownX, mDownY, mLastY);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
- mDraggingFastScroller = false;
- animateFastScrollerVisibility(false);
+ onFastScrollCompleted();
+ mScrollbar.handleTouchEvent(ev, mDownX, mDownY, mLastY);
break;
}
- return mDraggingFastScroller;
+ return mScrollbar.isDragging();
}
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
@@ -234,159 +169,117 @@
mBackgroundPadding.set(padding);
}
+ public Rect getBackgroundPadding() {
+ return mBackgroundPadding;
+ }
+
+ /**
+ * Returns the scroll bar width when the user is scrolling.
+ */
+ public int getMaxScrollbarWidth() {
+ return mScrollbar.getThumbMaxWidth();
+ }
+
+ /**
+ * Returns the available scroll height:
+ * AvailableScrollHeight = Total height of the all items - last page height
+ *
+ * This assumes that all rows are the same height.
+ *
+ * @param yOffset the offset from the top of the recycler view to start tracking.
+ */
+ protected int getAvailableScrollHeight(int rowCount, int rowHeight, int yOffset) {
+ int visibleHeight = getHeight() - mBackgroundPadding.top - mBackgroundPadding.bottom;
+ int scrollHeight = getPaddingTop() + yOffset + rowCount * rowHeight + getPaddingBottom();
+ int availableScrollHeight = scrollHeight - visibleHeight;
+ return availableScrollHeight;
+ }
+
+ /**
+ * Returns the available scroll bar height:
+ * AvailableScrollBarHeight = Total height of the visible view - thumb height
+ */
+ protected int getAvailableScrollBarHeight() {
+ int visibleHeight = getHeight() - mBackgroundPadding.top - mBackgroundPadding.bottom;
+ int availableScrollBarHeight = visibleHeight - mScrollbar.getThumbHeight();
+ return availableScrollBarHeight;
+ }
+
+ /**
+ * Returns the track color (ignoring alpha), can be overridden by each subclass.
+ */
+ public int getFastScrollerTrackColor(int defaultTrackColor) {
+ return defaultTrackColor;
+ }
+
+ /**
+ * Returns the inactive thumb color, can be overridden by each subclass.
+ */
+ public int getFastScrollerThumbInactiveColor(int defaultInactiveThumbColor) {
+ return defaultInactiveThumbColor;
+ }
+
@Override
protected void dispatchDraw(Canvas canvas) {
super.dispatchDraw(canvas);
- drawVerticalScrubber(canvas);
- drawFastScrollerPopup(canvas);
- }
-
- /**
- * Draws the vertical scrollbar.
- */
- private void drawVerticalScrubber(Canvas canvas) {
- updateVerticalScrollbarBounds();
-
- // Draw the scroll bar
- int restoreCount = canvas.save(Canvas.MATRIX_SAVE_FLAG);
- canvas.translate(verticalScrollbarBounds.left, verticalScrollbarBounds.top);
- mScrollbar.setBounds(0, 0, mScrollbarWidth, verticalScrollbarBounds.height());
+ onUpdateScrollbar();
mScrollbar.draw(canvas);
- canvas.restoreToCount(restoreCount);
}
/**
- * Draws the fast scroller popup.
+ * Updates the scrollbar thumb offset to match the visible scroll of the recycler view. It does
+ * this by mapping the available scroll area of the recycler view to the available space for the
+ * scroll bar.
+ *
+ * @param scrollPosState the current scroll position
+ * @param rowCount the number of rows, used to calculate the total scroll height (assumes that
+ * all rows are the same height)
+ * @param yOffset the offset to start tracking in the recycler view (only used for all apps)
*/
- private void drawFastScrollerPopup(Canvas canvas) {
- if (mFastScrollAlpha > 0f && mFastScrollSectionName != null && !mFastScrollSectionName.isEmpty()) {
- // Draw the fast scroller popup
- int restoreCount = canvas.save(Canvas.MATRIX_SAVE_FLAG);
- canvas.translate(mFastScrollerBounds.left, mFastScrollerBounds.top);
- mFastScrollerBg.setAlpha((int) (mFastScrollAlpha * 255));
- mFastScrollerBg.draw(canvas);
- mFastScrollTextPaint.setAlpha((int) (mFastScrollAlpha * 255));
- mFastScrollTextPaint.getTextBounds(mFastScrollSectionName, 0,
- mFastScrollSectionName.length(), mFastScrollTextBounds);
- float textWidth = mFastScrollTextPaint.measureText(mFastScrollSectionName);
- canvas.drawText(mFastScrollSectionName,
- (mFastScrollerBounds.width() - textWidth) / 2,
- mFastScrollerBounds.height() -
- (mFastScrollerBounds.height() - mFastScrollTextBounds.height()) / 2,
- mFastScrollTextPaint);
- canvas.restoreToCount(restoreCount);
+ protected void synchronizeScrollBarThumbOffsetToViewScroll(ScrollPositionState scrollPosState,
+ int rowCount, int yOffset) {
+ int availableScrollHeight = getAvailableScrollHeight(rowCount, scrollPosState.rowHeight,
+ yOffset);
+ int availableScrollBarHeight = getAvailableScrollBarHeight();
+
+ // Only show the scrollbar if there is height to be scrolled
+ if (availableScrollHeight <= 0) {
+ mScrollbar.setScrollbarThumbOffset(-1, -1);
+ return;
}
- }
- /**
- * Returns the scroll bar width.
- */
- public int getScrollbarWidth() {
- return mScrollbarWidth;
- }
+ // Calculate the current scroll position, the scrollY of the recycler view accounts for the
+ // view padding, while the scrollBarY is drawn right up to the background padding (ignoring
+ // padding)
+ int scrollY = getPaddingTop() + yOffset +
+ (scrollPosState.rowIndex * scrollPosState.rowHeight) - scrollPosState.rowTopOffset;
+ int scrollBarY = mBackgroundPadding.top +
+ (int) (((float) scrollY / availableScrollHeight) * availableScrollBarHeight);
- /**
- * Sets the fast scroller alpha.
- */
- public void setFastScrollerAlpha(float alpha) {
- mFastScrollAlpha = alpha;
- invalidateFastScroller(mFastScrollerBounds);
- }
-
- /**
- * Returns the fast scroller alpha.
- */
- public float getFastScrollerAlpha() {
- return mFastScrollAlpha;
+ // Calculate the position and size of the scroll bar
+ int scrollBarX;
+ if (Utilities.isRtl(getResources())) {
+ scrollBarX = mBackgroundPadding.left;
+ } else {
+ scrollBarX = getWidth() - mBackgroundPadding.right - mScrollbar.getWidth();
+ }
+ mScrollbar.setScrollbarThumbOffset(scrollBarX, scrollBarY);
}
/**
* Maps the touch (from 0..1) to the adapter position that should be visible.
* <p>Override in each subclass of this base class.
*/
- public String scrollToPositionAtProgress(float touchFraction) {
- return null;
- }
+ public abstract String scrollToPositionAtProgress(float touchFraction);
/**
* Updates the bounds for the scrollbar.
* <p>Override in each subclass of this base class.
*/
- public void updateVerticalScrollbarBounds() {};
+ public abstract void onUpdateScrollbar();
/**
- * Animates the visibility of the fast scroller popup.
+ * <p>Override in each subclass of this base class.
*/
- private void animateFastScrollerVisibility(final boolean visible) {
- ObjectAnimator anim = ObjectAnimator.ofFloat(this, "fastScrollerAlpha", visible ? 1f : 0f);
- anim.setDuration(visible ? 200 : 150);
- anim.addListener(new AnimatorListenerAdapter() {
- @Override
- public void onAnimationStart(Animator animation) {
- if (visible) {
- onFastScrollingStart();
- }
- }
-
- @Override
- public void onAnimationEnd(Animator animation) {
- if (!visible) {
- onFastScrollingEnd();
- }
- }
- });
- anim.start();
- }
-
- /**
- * To be overridden by subclasses.
- */
- protected void onFastScrollingStart() {}
-
- /**
- * To be overridden by subclasses.
- */
- protected void onFastScrollingEnd() {}
-
- /**
- * Invalidates the fast scroller popup.
- */
- protected void invalidateFastScroller(Rect bounds) {
- invalidate(bounds.left, bounds.top, bounds.right, bounds.bottom);
- }
-
- /**
- * Returns whether a given point is near the scrollbar.
- */
- private boolean isPointNearScrollbar(int x, int y) {
- // Check if we are scrolling
- updateVerticalScrollbarBounds();
- verticalScrollbarBounds.inset(mScrollbarInset, mScrollbarInset);
- return verticalScrollbarBounds.contains(x, y);
- }
-
- /**
- * Updates the bounds for the fast scroller.
- */
- private void updateFastScrollerBounds() {
- if (mFastScrollAlpha > 0f && !mFastScrollSectionName.isEmpty()) {
- int x;
- int y;
-
- // Calculate the position for the fast scroller popup
- Rect bgBounds = mFastScrollerBg.getBounds();
- if (Utilities.isRtl(getResources())) {
- x = mBackgroundPadding.left + (2 * getScrollbarWidth());
- } else {
- x = getWidth() - mBackgroundPadding.right - (2 * getScrollbarWidth()) -
- bgBounds.width();
- }
- y = mLastY - (int) (FAST_SCROLL_OVERLAY_Y_OFFSET_FACTOR * bgBounds.height());
- y = Math.max(getPaddingTop(), Math.min(y, getHeight() - getPaddingBottom() -
- bgBounds.height()));
- mFastScrollerBounds.set(x, y, x + bgBounds.width(), y + bgBounds.height());
- } else {
- mFastScrollerBounds.setEmpty();
- }
- }
+ public void onFastScrollCompleted() {}
}
\ No newline at end of file