Merge "Move AnimatedFloat from quickstep to launcher" into tm-qpr-dev

src/com/android/launcher3/anim/AnimatedFloat.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2022 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.anim;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.ObjectAnimator;
+import android.util.FloatProperty;
+
+/**
+ * A mutable float which allows animating the value
+ */
+public class AnimatedFloat {
+
+    public static final FloatProperty<AnimatedFloat> VALUE =
+            new FloatProperty<AnimatedFloat>("value") {
+                @Override
+                public void setValue(AnimatedFloat obj, float v) {
+                    obj.updateValue(v);
+                }
+
+                @Override
+                public Float get(AnimatedFloat obj) {
+                    return obj.value;
+                }
+            };
+
+    private static final Runnable NO_OP = () -> { };
+
+    private final Runnable mUpdateCallback;
+    private ObjectAnimator mValueAnimator;
+    // Only non-null when an animation is playing to this value.
+    private Float mEndValue;
+
+    public float value;
+
+    public AnimatedFloat() {
+        this(NO_OP);
+    }
+
+    public AnimatedFloat(Runnable updateCallback) {
+        mUpdateCallback = updateCallback;
+    }
+
+    /**
+     * Returns an animation from the current value to the given value.
+     */
+    public ObjectAnimator animateToValue(float end) {
+        return animateToValue(value, end);
+    }
+
+    /**
+     * Returns an animation from the given start value to the given end value.
+     */
+    public ObjectAnimator animateToValue(float start, float end) {
+        cancelAnimation();
+        mValueAnimator = ObjectAnimator.ofFloat(this, VALUE, start, end);
+        mValueAnimator.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationStart(Animator animator) {
+                if (mValueAnimator == animator) {
+                    mEndValue = end;
+                }
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animator) {
+                if (mValueAnimator == animator) {
+                    mValueAnimator = null;
+                    mEndValue = null;
+                }
+            }
+        });
+        return mValueAnimator;
+    }
+
+    /**
+     * Changes the value and calls the callback.
+     * Note that the value can be directly accessed as well to avoid notifying the callback.
+     */
+    public void updateValue(float v) {
+        if (Float.compare(v, value) != 0) {
+            value = v;
+            mUpdateCallback.run();
+        }
+    }
+
+    /**
+     * Cancels the animation.
+     */
+    public void cancelAnimation() {
+        if (mValueAnimator != null) {
+            mValueAnimator.cancel();
+        }
+    }
+
+    /**
+     * Ends the animation.
+     */
+    public void finishAnimation() {
+        if (mValueAnimator != null && mValueAnimator.isRunning()) {
+            mValueAnimator.end();
+        }
+    }
+
+    public boolean isAnimating() {
+        return mValueAnimator != null;
+    }
+
+    /**
+     * Returns whether we are currently animating, and the animation's end value matches the given.
+     */
+    public boolean isAnimatingToValue(float endValue) {
+        return isAnimating() && mEndValue != null && mEndValue == endValue;
+    }
+
+    /**
+     * Returns whether we are currently not animating, and the animation's value matches the given.
+     */
+    public boolean isSettledOnValue(float endValue) {
+        return !isAnimating() && value == endValue;
+    }
+}