Fixing RTL wallpaper scrolling.
- Ensure that we map the scroll offsets to the full wallpaper offset
range
- Default to either edge of the wallpaper (depending on RTL) to match
the default system wallpaper behavior (ag/1265418)
Bug: 28795125
Bug: 29398681
Change-Id: I36c316095057912d2dda0beb43bd1e6aaeac3fdc
diff --git a/src/com/android/launcher3/util/WallpaperOffsetInterpolator.java b/src/com/android/launcher3/util/WallpaperOffsetInterpolator.java
index 1fbd0dc..1568beb 100644
--- a/src/com/android/launcher3/util/WallpaperOffsetInterpolator.java
+++ b/src/com/android/launcher3/util/WallpaperOffsetInterpolator.java
@@ -18,7 +18,7 @@
private static final int ANIMATION_DURATION = 250;
// Don't use all the wallpaper for parallax until you have at least this many pages
- private static final int MIN_PARALLAX_PAGE_SPAN = 3;
+ private static final int MIN_PARALLAX_PAGE_SPAN = 4;
private final Choreographer mChoreographer;
private final Interpolator mInterpolator;
@@ -90,57 +90,60 @@
return false;
}
+ /**
+ * TODO: do different behavior if it's a live wallpaper?
+ */
public float wallpaperOffsetForScroll(int scroll) {
- // TODO: do different behavior if it's a live wallpaper?
- // Don't use up all the wallpaper parallax until you have at least
- // MIN_PARALLAX_PAGE_SPAN pages
+ // To match the default wallpaper behavior in the system, we default to either the left
+ // or right edge on initialization
int numScrollingPages = getNumScreensExcludingEmptyAndCustom();
- int parallaxPageSpan;
+ if (numScrollingPages <= 1) {
+ return mIsRtl ? 1f : 0f;
+ }
+
+ // Distribute the wallpaper parallax over a minimum of MIN_PARALLAX_PAGE_SPAN workspace
+ // screens, not including the custom screen, and empty screens (if > MIN_PARALLAX_PAGE_SPAN)
if (mWallpaperIsLiveWallpaper) {
- parallaxPageSpan = numScrollingPages - 1;
+ mNumPagesForWallpaperParallax = numScrollingPages;
} else {
- parallaxPageSpan = Math.max(MIN_PARALLAX_PAGE_SPAN, numScrollingPages - 1);
- }
- mNumPagesForWallpaperParallax = parallaxPageSpan;
-
- if (mWorkspace.getChildCount() <= 1) {
- if (mIsRtl) {
- return 1 - 1.0f/mNumPagesForWallpaperParallax;
- }
- return 0;
+ mNumPagesForWallpaperParallax = Math.max(MIN_PARALLAX_PAGE_SPAN, numScrollingPages);
}
- // Exclude the leftmost page
- int emptyExtraPages = numEmptyScreensToIgnore();
- int firstIndex = mWorkspace.numCustomPages();
- // Exclude the last extra empty screen (if we have > MIN_PARALLAX_PAGE_SPAN pages)
- int lastIndex = mWorkspace.getChildCount() - 1 - emptyExtraPages;
+ // Offset by the custom screen
+ int leftPageIndex;
+ int rightPageIndex;
if (mIsRtl) {
- int temp = firstIndex;
- firstIndex = lastIndex;
- lastIndex = temp;
- }
-
- int firstPageScrollX = mWorkspace.getScrollForPage(firstIndex);
- int scrollRange = mWorkspace.getScrollForPage(lastIndex) - firstPageScrollX;
- if (scrollRange == 0) {
- return 0;
+ rightPageIndex = mWorkspace.numCustomPages();
+ leftPageIndex = rightPageIndex + numScrollingPages - 1;
} else {
- // Sometimes the left parameter of the pages is animated during a layout transition;
- // this parameter offsets it to keep the wallpaper from animating as well
- int adjustedScroll =
- scroll - firstPageScrollX - mWorkspace.getLayoutTransitionOffsetForPage(0);
- float offset = Math.min(1, adjustedScroll / (float) scrollRange);
- offset = Math.max(0, offset);
-
- // On RTL devices, push the wallpaper offset to the right if we don't have enough
- // pages (ie if numScrollingPages < MIN_PARALLAX_PAGE_SPAN)
- if (!mWallpaperIsLiveWallpaper && numScrollingPages < MIN_PARALLAX_PAGE_SPAN
- && mIsRtl) {
- return offset * (parallaxPageSpan - numScrollingPages + 1) / parallaxPageSpan;
- }
- return offset * (numScrollingPages - 1) / parallaxPageSpan;
+ leftPageIndex = mWorkspace.numCustomPages();
+ rightPageIndex = leftPageIndex + numScrollingPages - 1;
}
+
+ // Calculate the scroll range
+ int leftPageScrollX = mWorkspace.getScrollForPage(leftPageIndex);
+ int rightPageScrollX = mWorkspace.getScrollForPage(rightPageIndex);
+ int scrollRange = rightPageScrollX - leftPageScrollX;
+ if (scrollRange == 0) {
+ return 0f;
+ }
+
+ // Sometimes the left parameter of the pages is animated during a layout transition;
+ // this parameter offsets it to keep the wallpaper from animating as well
+ int adjustedScroll = scroll - leftPageScrollX -
+ mWorkspace.getLayoutTransitionOffsetForPage(0);
+ float offset = Utilities.boundToRange((float) adjustedScroll / scrollRange, 0f, 1f);
+
+ // The offset is now distributed 0..1 between the left and right pages that we care about,
+ // so we just map that between the pages that we are using for parallax
+ float rtlOffset = 0;
+ if (mIsRtl) {
+ // In RTL, the pages are right aligned, so adjust the offset from the end
+ rtlOffset = (float) ((mNumPagesForWallpaperParallax - 1) - (numScrollingPages - 1)) /
+ (mNumPagesForWallpaperParallax - 1);
+ }
+ return rtlOffset + offset *
+ ((float) (numScrollingPages - 1) / (mNumPagesForWallpaperParallax - 1));
}
private float wallpaperOffsetForCurrentScroll() {
@@ -182,7 +185,7 @@
private void setWallpaperOffsetSteps() {
// Set wallpaper offset steps (1 / (number of screens - 1))
- float xOffset = 1.0f / mNumPagesForWallpaperParallax;
+ float xOffset = 1.0f / (mNumPagesForWallpaperParallax - 1);
if (xOffset != mLastSetWallpaperOffsetSteps) {
mWallpaperManager.setWallpaperOffsetSteps(xOffset, 1.0f);
mLastSetWallpaperOffsetSteps = xOffset;
