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author | Michael Jurka <mikejurka@google.com> | 2010-08-25 17:46:15 -0700 |
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committer | Michael Jurka <mikejurka@google.com> | 2010-09-01 14:54:34 -0700 |
commit | 0142d49e1378a7155bcca1fb59965d9e73016dbc (patch) | |
tree | 36d700bbf061564e34f359c2ef009ede5f88d20f /src/com/android/launcher2/SmoothPagedView.java | |
parent | 6b4adbc0558fcebbd44998bd00dcd334ddbee32d (diff) | |
download | packages_apps_trebuchet-0142d49e1378a7155bcca1fb59965d9e73016dbc.zip packages_apps_trebuchet-0142d49e1378a7155bcca1fb59965d9e73016dbc.tar.gz packages_apps_trebuchet-0142d49e1378a7155bcca1fb59965d9e73016dbc.tar.bz2 |
Changed Workspace to inherit from PagedView
- adds support for seeing dimmed side-pages on
home
- adds workspace support for pages that are
smaller than workspace itself
- removing a lot of code duplicated between
PagedView and Workspace
- tested new Workspace on Nexus One, and perf.
was indistinguishable from old Workspace in my
tests
Change-Id: Ie33ab4e8b35ac01b22894cff66650bb0ece8dfcc
Diffstat (limited to 'src/com/android/launcher2/SmoothPagedView.java')
-rw-r--r-- | src/com/android/launcher2/SmoothPagedView.java | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/src/com/android/launcher2/SmoothPagedView.java b/src/com/android/launcher2/SmoothPagedView.java new file mode 100644 index 0000000..3218349 --- /dev/null +++ b/src/com/android/launcher2/SmoothPagedView.java @@ -0,0 +1,159 @@ +/* + * Copyright (C) 2008 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.android.launcher2; + +import android.content.Context; +import android.util.AttributeSet; +import android.view.animation.Interpolator; +import android.widget.Scroller; + + +public abstract class SmoothPagedView extends PagedView { + private static final float SMOOTHING_SPEED = 0.75f; + private static final float SMOOTHING_CONSTANT = (float) (0.016 / Math.log(SMOOTHING_SPEED)); + + + private static final float BASELINE_FLING_VELOCITY = 2500.f; + private static final float FLING_VELOCITY_INFLUENCE = 0.4f; + + private WorkspaceOvershootInterpolator mScrollInterpolator; + + private static class WorkspaceOvershootInterpolator implements Interpolator { + private static final float DEFAULT_TENSION = 1.3f; + private float mTension; + + public WorkspaceOvershootInterpolator() { + mTension = DEFAULT_TENSION; + } + + public void setDistance(int distance) { + mTension = distance > 0 ? DEFAULT_TENSION / distance : DEFAULT_TENSION; + } + + public void disableSettle() { + mTension = 0.f; + } + + public float getInterpolation(float t) { + // _o(t) = t * t * ((tension + 1) * t + tension) + // o(t) = _o(t - 1) + 1 + t -= 1.0f; + return t * t * ((mTension + 1) * t + mTension) + 1.0f; + } + } + + /** + * Used to inflate the Workspace from XML. + * + * @param context The application's context. + * @param attrs The attributes set containing the Workspace's customization values. + */ + public SmoothPagedView(Context context, AttributeSet attrs) { + this(context, attrs, 0); + } + + /** + * Used to inflate the Workspace from XML. + * + * @param context The application's context. + * @param attrs The attributes set containing the Workspace's customization values. + * @param defStyle Unused. + */ + public SmoothPagedView(Context context, AttributeSet attrs, int defStyle) { + super(context, attrs, defStyle); + + mUsePagingTouchSlop = false; + + // This means that we'll take care of updating the scroll parameter ourselves (we do it + // in computeScroll) + mDeferScrollUpdate = true; + } + + /** + * Initializes various states for this workspace. + */ + @Override + protected void init() { + super.init(); + mScrollInterpolator = new WorkspaceOvershootInterpolator(); + // overwrite the previous mScroller + mScroller = new Scroller(getContext(), mScrollInterpolator); + } + + @Override + protected void snapToDestination() { + snapToPageWithVelocity(mCurrentPage, 0); + } + + @Override + protected void snapToPageWithVelocity(int whichPage, int velocity) { + snapToPageWithVelocity(whichPage, 0, true); + } + + void snapToPageWithVelocity(int whichPage, int velocity, boolean settle) { + // if (!mScroller.isFinished()) return; + + whichPage = Math.max(0, Math.min(whichPage, getChildCount() - 1)); + + final int screenDelta = Math.max(1, Math.abs(whichPage - mCurrentPage)); + final int newX = whichPage * getWidth(); + final int delta = newX - mScrollX; + int duration = (screenDelta + 1) * 100; + + if (!mScroller.isFinished()) { + mScroller.abortAnimation(); + } + + if (settle) { + mScrollInterpolator.setDistance(screenDelta); + } else { + mScrollInterpolator.disableSettle(); + } + + velocity = Math.abs(velocity); + if (velocity > 0) { + duration += (duration / (velocity / BASELINE_FLING_VELOCITY)) + * FLING_VELOCITY_INFLUENCE; + } else { + duration += 100; + } + snapToPage(whichPage, delta, duration); + } + + @Override + protected void snapToPage(int whichPage) { + snapToPageWithVelocity(whichPage, 0, false); + } + + @Override + public void computeScroll() { + boolean scrollComputed = computeScrollHelper(); + + if (!scrollComputed && mTouchState == TOUCH_STATE_SCROLLING) { + final float now = System.nanoTime() / NANOTIME_DIV; + final float e = (float) Math.exp((now - mSmoothingTime) / SMOOTHING_CONSTANT); + final float dx = mTouchX - mScrollX; + mScrollX += dx * e; + mSmoothingTime = now; + + // Keep generating points as long as we're more than 1px away from the target + if (dx > 1.f || dx < -1.f) { + invalidate(); + } + } + } +} |