Lawnchair/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java

/*
 * Copyright (C) 2015 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;

import static androidx.dynamicanimation.animation.DynamicAnimation.MIN_VISIBLE_CHANGE_SCALE;

import static com.android.launcher3.LauncherAnimUtils.DRAWABLE_ALPHA;
import static com.android.launcher3.LauncherAnimUtils.SCALE_PROPERTY;
import static com.android.launcher3.LauncherAnimUtils.VIEW_ALPHA;
import static com.android.launcher3.LauncherAnimUtils.VIEW_TRANSLATE_X;
import static com.android.launcher3.LauncherAnimUtils.VIEW_TRANSLATE_Y;
import static com.android.launcher3.LauncherState.FLAG_HAS_SYS_UI_SCRIM;
import static com.android.launcher3.LauncherState.FLAG_WORKSPACE_HAS_BACKGROUNDS;
import static com.android.launcher3.LauncherState.HINT_STATE;
import static com.android.launcher3.LauncherState.HOTSEAT_ICONS;
import static com.android.launcher3.LauncherState.NORMAL;
import static com.android.launcher3.LauncherState.WORKSPACE_PAGE_INDICATOR;
import static com.android.launcher3.anim.Interpolators.LINEAR;
import static com.android.launcher3.anim.Interpolators.ZOOM_OUT;
import static com.android.launcher3.anim.PropertySetter.NO_ANIM_PROPERTY_SETTER;
import static com.android.launcher3.graphics.Scrim.SCRIM_PROGRESS;
import static com.android.launcher3.graphics.SysUiScrim.SYSUI_PROGRESS;
import static com.android.launcher3.states.StateAnimationConfig.ANIM_HOTSEAT_SCALE;
import static com.android.launcher3.states.StateAnimationConfig.ANIM_HOTSEAT_TRANSLATE;
import static com.android.launcher3.states.StateAnimationConfig.ANIM_WORKSPACE_FADE;
import static com.android.launcher3.states.StateAnimationConfig.ANIM_WORKSPACE_SCALE;
import static com.android.launcher3.states.StateAnimationConfig.ANIM_WORKSPACE_SCRIM_FADE;
import static com.android.launcher3.states.StateAnimationConfig.ANIM_WORKSPACE_TRANSLATE;
import static com.android.launcher3.states.StateAnimationConfig.SKIP_SCRIM;

import android.animation.ValueAnimator;
import android.view.View;
import android.view.animation.Interpolator;

import com.android.launcher3.LauncherState.PageAlphaProvider;
import com.android.launcher3.LauncherState.ScaleAndTranslation;
import com.android.launcher3.anim.PendingAnimation;
import com.android.launcher3.anim.PropertySetter;
import com.android.launcher3.anim.SpringAnimationBuilder;
import com.android.launcher3.graphics.SysUiScrim;
import com.android.launcher3.graphics.WorkspaceDragScrim;
import com.android.launcher3.states.StateAnimationConfig;
import com.android.launcher3.util.DynamicResource;
import com.android.systemui.plugins.ResourceProvider;

/**
 * Manages the animations between each of the workspace states.
 */
public class WorkspaceStateTransitionAnimation {

    private final Launcher mLauncher;
    private final Workspace mWorkspace;

    private float mNewScale;

    public WorkspaceStateTransitionAnimation(Launcher launcher, Workspace workspace) {
        mLauncher = launcher;
        mWorkspace = workspace;
    }

    public void setState(LauncherState toState) {
        setWorkspaceProperty(toState, NO_ANIM_PROPERTY_SETTER, new StateAnimationConfig());
    }

    /**
     * @see com.android.launcher3.statemanager.StateManager.StateHandler#setStateWithAnimation
     */
    public void setStateWithAnimation(
            LauncherState toState, StateAnimationConfig config, PendingAnimation animation) {
        setWorkspaceProperty(toState, animation, config);
    }

    public float getFinalScale() {
        return mNewScale;
    }

    /**
     * Starts a transition animation for the workspace.
     */
    private void setWorkspaceProperty(LauncherState state, PropertySetter propertySetter,
            StateAnimationConfig config) {
        ScaleAndTranslation scaleAndTranslation = state.getWorkspaceScaleAndTranslation(mLauncher);
        ScaleAndTranslation hotseatScaleAndTranslation = state.getHotseatScaleAndTranslation(
                mLauncher);
        mNewScale = scaleAndTranslation.scale;
        PageAlphaProvider pageAlphaProvider = state.getWorkspacePageAlphaProvider(mLauncher);
        final int childCount = mWorkspace.getChildCount();
        for (int i = 0; i < childCount; i++) {
            applyChildState(state, (CellLayout) mWorkspace.getChildAt(i), i, pageAlphaProvider,
                    propertySetter, config);
        }

        int elements = state.getVisibleElements(mLauncher);
        Interpolator fadeInterpolator = config.getInterpolator(ANIM_WORKSPACE_FADE,
                pageAlphaProvider.interpolator);
        Hotseat hotseat = mWorkspace.getHotseat();
        Interpolator scaleInterpolator = config.getInterpolator(ANIM_WORKSPACE_SCALE, ZOOM_OUT);
        LauncherState fromState = mLauncher.getStateManager().getState();

        boolean shouldSpring = propertySetter instanceof PendingAnimation
                && fromState == HINT_STATE && state == NORMAL;
        if (shouldSpring) {
            ((PendingAnimation) propertySetter).add(getSpringScaleAnimator(mLauncher,
                    mWorkspace, mNewScale));
        } else {
            propertySetter.setFloat(mWorkspace, SCALE_PROPERTY, mNewScale, scaleInterpolator);
        }

        setPivotToScaleWithWorkspace(hotseat);
        float hotseatScale = hotseatScaleAndTranslation.scale;
        if (shouldSpring) {
            PendingAnimation pa = (PendingAnimation) propertySetter;
            pa.add(getSpringScaleAnimator(mLauncher, hotseat, hotseatScale));
        } else {
            Interpolator hotseatScaleInterpolator = config.getInterpolator(ANIM_HOTSEAT_SCALE,
                    scaleInterpolator);
            propertySetter.setFloat(hotseat, SCALE_PROPERTY, hotseatScale,
                    hotseatScaleInterpolator);
        }

        float hotseatIconsAlpha = (elements & HOTSEAT_ICONS) != 0 ? 1 : 0;
        propertySetter.setViewAlpha(hotseat, hotseatIconsAlpha, fadeInterpolator);
        float workspacePageIndicatorAlpha = (elements & WORKSPACE_PAGE_INDICATOR) != 0 ? 1 : 0;
        propertySetter.setViewAlpha(mLauncher.getWorkspace().getPageIndicator(),
                workspacePageIndicatorAlpha, fadeInterpolator);

        Interpolator translationInterpolator =
                config.getInterpolator(ANIM_WORKSPACE_TRANSLATE, ZOOM_OUT);
        propertySetter.setFloat(mWorkspace, VIEW_TRANSLATE_X,
                scaleAndTranslation.translationX, translationInterpolator);
        propertySetter.setFloat(mWorkspace, VIEW_TRANSLATE_Y,
                scaleAndTranslation.translationY, translationInterpolator);

        Interpolator hotseatTranslationInterpolator = config.getInterpolator(
                ANIM_HOTSEAT_TRANSLATE, translationInterpolator);
        propertySetter.setFloat(hotseat, VIEW_TRANSLATE_Y,
                hotseatScaleAndTranslation.translationY, hotseatTranslationInterpolator);
        propertySetter.setFloat(mWorkspace.getPageIndicator(), VIEW_TRANSLATE_Y,
                hotseatScaleAndTranslation.translationY, hotseatTranslationInterpolator);

        if (!config.hasAnimationFlag(SKIP_SCRIM)) {
            setScrim(propertySetter, state, config);
        }
    }

    /**
     * Set the given view's pivot point to match the workspace's, so that it scales together. Since
     * both this view and workspace can move, transform the point manually instead of using
     * dragLayer.getDescendantCoordRelativeToSelf and related methods.
     */
    private void setPivotToScaleWithWorkspace(View sibling) {
        sibling.setPivotY(mWorkspace.getPivotY() + mWorkspace.getTop()
                - sibling.getTop() - sibling.getTranslationY());
        sibling.setPivotX(mWorkspace.getPivotX() + mWorkspace.getLeft()
                - sibling.getLeft() - sibling.getTranslationX());
    }

    public void setScrim(PropertySetter propertySetter, LauncherState state,
            StateAnimationConfig config) {
        WorkspaceDragScrim workspaceDragScrim = mLauncher.getDragLayer().getWorkspaceDragScrim();
        propertySetter.setFloat(workspaceDragScrim, SCRIM_PROGRESS,
                state.getWorkspaceBackgroundAlpha(mLauncher), LINEAR);

        SysUiScrim sysUiScrim = mLauncher.getDragLayer().getSysUiScrim();
        propertySetter.setFloat(sysUiScrim, SYSUI_PROGRESS,
                state.hasFlag(FLAG_HAS_SYS_UI_SCRIM) ? 1 : 0, LINEAR);

        propertySetter.setViewAlpha(mLauncher.getScrimView(),
                state.getWorkspaceScrimAlpha(mLauncher),
                config.getInterpolator(ANIM_WORKSPACE_SCRIM_FADE, LINEAR));
    }

    public void applyChildState(LauncherState state, CellLayout cl, int childIndex) {
        applyChildState(state, cl, childIndex, state.getWorkspacePageAlphaProvider(mLauncher),
                NO_ANIM_PROPERTY_SETTER, new StateAnimationConfig());
    }

    private void applyChildState(LauncherState state, CellLayout cl, int childIndex,
            PageAlphaProvider pageAlphaProvider, PropertySetter propertySetter,
            StateAnimationConfig config) {
        float pageAlpha = pageAlphaProvider.getPageAlpha(childIndex);
        int drawableAlpha = state.hasFlag(FLAG_WORKSPACE_HAS_BACKGROUNDS)
                ? Math.round(pageAlpha * 255) : 0;

        propertySetter.setInt(cl.getScrimBackground(),
                DRAWABLE_ALPHA, drawableAlpha, ZOOM_OUT);
        Interpolator fadeInterpolator = config.getInterpolator(ANIM_WORKSPACE_FADE,
                pageAlphaProvider.interpolator);
        propertySetter.setFloat(cl.getShortcutsAndWidgets(), VIEW_ALPHA,
                pageAlpha, fadeInterpolator);
    }

    /**
     * Returns a spring based animator for the scale property of {@param v}.
     */
    public static ValueAnimator getSpringScaleAnimator(Launcher launcher, View v, float scale) {
        ResourceProvider rp = DynamicResource.provider(launcher);
        float damping = rp.getFloat(R.dimen.hint_scale_damping_ratio);
        float stiffness = rp.getFloat(R.dimen.hint_scale_stiffness);
        float velocityPxPerS = rp.getDimension(R.dimen.hint_scale_velocity_dp_per_s);

        return new SpringAnimationBuilder(v.getContext())
                .setStiffness(stiffness)
                .setDampingRatio(damping)
                .setMinimumVisibleChange(MIN_VISIBLE_CHANGE_SCALE)
                .setEndValue(scale)
                .setStartValue(SCALE_PROPERTY.get(v))
                .setStartVelocity(velocityPxPerS)
                .build(v, SCALE_PROPERTY);

    }
}