src/com/android/launcher3/touch/DefaultPagedViewHandler.java

/*
 * Copyright (C) 2019 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.touch;

import android.content.res.Resources;
import android.graphics.Rect;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.accessibility.AccessibilityEvent;

import com.android.launcher3.Utilities;

public class DefaultPagedViewHandler implements PagedOrientationHandler {
    @Override
    public int getPrimaryValue(int x, int y) {
        return x;
    }

    @Override
    public int getSecondaryValue(int x, int y) {
        return y;
    }

    @Override
    public float getPrimaryValue(float x, float y) {
        return x;
    }

    @Override
    public float getSecondaryValue(float x, float y) {
        return y;
    }

    @Override
    public <T> void setPrimary(T target, Int2DAction<T> action, int param) {
        action.call(target, param, 0);
    }

    @Override
    public <T> void setPrimary(T target, Float2DAction<T> action, float param) {
        action.call(target, param, 0);
    }

    @Override
    public float getPrimaryDirection(MotionEvent event, int pointerIndex) {
        return event.getX(pointerIndex);
    }

    @Override
    public float getPrimaryVelocity(VelocityTracker velocityTracker, int pointerId) {
        return velocityTracker.getXVelocity(pointerId);
    }

    @Override
    public int getMeasuredSize(View view) {
        return view.getMeasuredWidth();
    }

    @Override
    public int getPrimaryScroll(View view) {
        return view.getScrollX();
    }

    @Override
    public float getPrimaryScale(View view) {
        return view.getScaleX();
    }

    @Override
    public void setMaxScroll(AccessibilityEvent event, int maxScroll) {
        event.setMaxScrollX(maxScroll);
    }

    @Override
    public boolean getRecentsRtlSetting(Resources resources) {
        return !Utilities.isRtl(resources);
    }

    @Override
    public int getChildStart(View view) {
        return view.getLeft();
    }

    @Override
    public int getCenterForPage(View view, Rect insets) {
        return (view.getPaddingTop() + view.getMeasuredHeight() + insets.top
            - insets.bottom - view.getPaddingBottom()) / 2;
    }

    @Override
    public int getScrollOffsetStart(View view, Rect insets) {
        return insets.left + view.getPaddingLeft();
    }

    @Override
    public int getScrollOffsetEnd(View view, Rect insets) {
        return view.getWidth() - view.getPaddingRight() - insets.right;
    }

    @Override
    public ChildBounds getChildBounds(View child, int childStart, int pageCenter,
            boolean layoutChild) {
        final int childWidth = child.getMeasuredWidth();
        final int childRight = childStart + childWidth;
        final int childHeight = child.getMeasuredHeight();
        final int childTop = pageCenter - childHeight / 2;
        if (layoutChild) {
            child.layout(childStart, childTop, childRight, childTop + childHeight);
        }
        return new ChildBounds(childWidth, childHeight, childRight, childTop);
    }

}