Simpler caret

Bug: 30527159 Change-Id: I674de149e613c7adb567a13a288baa9877d36112
2016-07-29 17:05:30 -07:00
parent a659bfe3d2
commit e6fe1b5947
3 changed files with 129 additions and 67 deletions
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2016 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.launcher3.allapps;
+
+import android.animation.ObjectAnimator;
+import android.view.animation.AnimationUtils;
+import android.view.animation.Interpolator;
+
+import com.android.launcher3.Launcher;
+import com.android.launcher3.R;
+import com.android.launcher3.pageindicators.CaretDrawable;
+
+public class AllAppsCaretController {
+    // Determines when the caret should flip. Should be accessed via getThreshold()
+    private static final float CARET_THRESHOLD = 0.015f;
+    private static final float CARET_THRESHOLD_LAND = 0.5f;
+    // The velocity at which the caret will peak (i.e. exhibit a 90 degree bend)
+    private static final float PEAK_VELOCITY = VerticalPullDetector.RELEASE_VELOCITY_PX_MS * .7f;
+
+    private Launcher mLauncher;
+
+    private ObjectAnimator mCaretAnimator;
+    private CaretDrawable mCaretDrawable;
+    private float mLastCaretProgress;
+    private boolean mThresholdCrossed;
+
+    public AllAppsCaretController(CaretDrawable caret, Launcher launcher) {
+        mLauncher = launcher;
+        mCaretDrawable = caret;
+
+        final long caretAnimationDuration = launcher.getResources().getInteger(
+                R.integer.config_caretAnimationDuration);
+        final Interpolator caretInterpolator = AnimationUtils.loadInterpolator(launcher,
+                android.R.interpolator.fast_out_slow_in);
+
+        // We will set values later
+        mCaretAnimator = ObjectAnimator.ofFloat(mCaretDrawable, "caretProgress", 0);
+        mCaretAnimator.setDuration(caretAnimationDuration);
+        mCaretAnimator.setInterpolator(caretInterpolator);
+    }
+
+    /**
+     * Updates the state of the caret based on the progress of the {@link AllAppsContainerView}, as
+     * defined by the {@link AllAppsTransitionController}. Uses the container's velocity to adjust
+     * angle of caret.
+     *
+     * @param containerProgress The progress of the container in the range [0..1]
+     * @param velocity The velocity of the container
+     * @param dragging {@code true} if the container is being dragged
+     */
+    public void updateCaret(float containerProgress, float velocity, boolean dragging) {
+        // If we're in portrait and the shift is not 0 or 1, adjust the caret based on velocity
+        if (getThreshold() < containerProgress && containerProgress < 1 - getThreshold() &&
+                !mLauncher.useVerticalBarLayout()) {
+            mThresholdCrossed = true;
+
+            // How fast are we moving as a percentage of the peak velocity?
+            final float pctOfFlingVelocity = Math.max(-1, Math.min(velocity / PEAK_VELOCITY, 1));
+
+            mCaretDrawable.setCaretProgress(pctOfFlingVelocity);
+
+            // Set the last caret progress to this progress to prevent animator cancellation
+            mLastCaretProgress = pctOfFlingVelocity;
+            // Animate to neutral. This is necessary so the caret doesn't "freeze" when the
+            // container stops moving (e.g., during a drag or when the threshold is reached).
+            animateCaretToProgress(CaretDrawable.PROGRESS_CARET_NEUTRAL);
+        } else if (!dragging) {
+            // Otherwise, if we're not dragging, match the caret to the appropriate state
+            if (containerProgress <= getThreshold()) { // All Apps is up
+                animateCaretToProgress(CaretDrawable.PROGRESS_CARET_POINTING_DOWN);
+            } else if (containerProgress >= 1 - getThreshold()) { // All Apps is down
+                animateCaretToProgress(CaretDrawable.PROGRESS_CARET_POINTING_UP);
+            }
+        }
+    }
+
+    private void animateCaretToProgress(float progress) {
+        // If the new progress is the same as the last progress we animated to, terminate early
+        if (Float.compare(mLastCaretProgress, progress) == 0) {
+            return;
+        }
+
+        if (mCaretAnimator.isRunning()) {
+            mCaretAnimator.cancel(); // Stop the animator in its tracks
+        }
+
+        // Update the progress and start the animation
+        mLastCaretProgress = progress;
+        mCaretAnimator.setFloatValues(progress);
+        mCaretAnimator.start();
+    }
+
+    private float getThreshold() {
+        // In landscape, just return the landscape threshold.
+        if (mLauncher.useVerticalBarLayout()) {
+            return CARET_THRESHOLD_LAND;
+        }
+
+        // Before the threshold is crossed, it is reported as zero. This makes the caret immediately
+        // responsive when a drag begins. After the threshold is crossed, we return the constant
+        // value. This means the caret will start its state-based adjustment sooner. That is, we
+        // won't have to wait until the panel is completely settled to begin animation.
+        return mThresholdCrossed ? CARET_THRESHOLD : 0f;
+    }
+
+    public void onDragStart() {
+        mThresholdCrossed = false;
+    }
+}