1 files changed, 77 insertions, 0 deletions
diff --git a/src/com/android/launcher3/PinchThresholdManager.java b/src/com/android/launcher3/PinchThresholdManager.java
new file mode 100644
index 000000000..d79a63174
--- /dev/null
+++ b/src/com/android/launcher3/PinchThresholdManager.java
@@ -0,0 +1,77 @@
+package com.android.launcher3;
+
+/**
+ * Keeps track of when thresholds are passed during a pinch gesture,
+ * used to inform {@link PinchAnimationManager} throughout.
+ *
+ * @see PinchToOverviewListener
+ * @see PinchAnimationManager
+ */
+public class PinchThresholdManager {
+    public static final float THRESHOLD_ZERO = 0.0f;
+    public static final float THRESHOLD_ONE = 0.40f;
+    public static final float THRESHOLD_TWO = 0.70f;
+    public static final float THRESHOLD_THREE = 0.95f;
+
+    private Workspace mWorkspace;
+
+    private float mPassedThreshold = THRESHOLD_ZERO;
+
+    public PinchThresholdManager(Workspace workspace) {
+        mWorkspace = workspace;
+    }
+
+    /**
+     * Uses the pinch progress to determine whether a threshold has been passed,
+     * and asks the {@param animationManager} to animate if so.
+     * @param progress From 0 to 1, where 0 is overview and 1 is workspace.
+     * @param animationManager Animates the threshold change if one is passed.
+     * @return The last passed threshold, one of
+     *         {@link PinchThresholdManager#THRESHOLD_ZERO},
+     *         {@link PinchThresholdManager#THRESHOLD_ONE},
+     *         {@link PinchThresholdManager#THRESHOLD_TWO}, or
+     *         {@link PinchThresholdManager#THRESHOLD_THREE}
+     */
+    public float updateAndAnimatePassedThreshold(float progress,
+            PinchAnimationManager animationManager) {
+        if (!mWorkspace.isInOverviewMode()) {
+            // Invert the progress, because going from workspace to overview is 1 to 0.
+            progress = 1f - progress;
+        }
+
+        float previousPassedThreshold = mPassedThreshold;
+
+        if (progress < THRESHOLD_ONE) {
+            mPassedThreshold = THRESHOLD_ZERO;
+        } else if (progress < THRESHOLD_TWO) {
+            mPassedThreshold = THRESHOLD_ONE;
+        } else if (progress < THRESHOLD_THREE) {
+            mPassedThreshold = THRESHOLD_TWO;
+        } else {
+            mPassedThreshold = THRESHOLD_THREE;
+        }
+
+        if (mPassedThreshold != previousPassedThreshold) {
+            Workspace.State fromState = mWorkspace.isInOverviewMode() ? Workspace.State.OVERVIEW
+                    : Workspace.State.NORMAL;
+            Workspace.State toState = mWorkspace.isInOverviewMode() ? Workspace.State.NORMAL
+                    : Workspace.State.OVERVIEW;
+            float thresholdToAnimate = mPassedThreshold;
+            if (mPassedThreshold < previousPassedThreshold) {
+                // User reversed pinch, so heading back to the state that they started from.
+                toState = fromState;
+                thresholdToAnimate = previousPassedThreshold;
+            }
+            animationManager.animateThreshold(thresholdToAnimate, fromState, toState);
+        }
+        return mPassedThreshold;
+    }
+
+    public float getPassedThreshold() {
+        return mPassedThreshold;
+    }
+
+    public void reset() {
+        mPassedThreshold = THRESHOLD_ZERO;
+    }
+}