ui/android/java/src/org/chromium/ui/widget/Toast.java

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package org.chromium.ui.widget;

import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.ContextWrapper;
import android.content.pm.ApplicationInfo;
import android.content.res.Resources;
import android.os.Build;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;

import org.chromium.base.SysUtils;

/**
 * Toast wrapper, makes sure toasts are not HW accelerated on low-end devices and presented
 * correctly (i.e. use VrToast while in virtual reality).
 *
 * Can (and should) also be used for Chromium-related additions and extensions.
 */
public class Toast {

    public static final int LENGTH_SHORT = android.widget.Toast.LENGTH_SHORT;
    public static final int LENGTH_LONG = android.widget.Toast.LENGTH_LONG;

    private static int sExtraYOffset;

    private android.widget.Toast mToast;
    private ViewGroup mSWLayout;

    public Toast(Context context) {
        this(context, UiWidgetFactory.getInstance().createToast(context));
    }

    private Toast(Context context, android.widget.Toast toast) {
        mToast = toast;

        if (SysUtils.isLowEndDevice() && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            // Don't HW accelerate Toasts. Unfortunately the only way to do that is to make
            // toast.getView().getContext().getApplicationInfo() return lies to prevent
            // WindowManagerGlobal.addView() from adding LayoutParams.FLAG_HARDWARE_ACCELERATED.
            mSWLayout = new FrameLayout(new ContextWrapper(context) {
                @Override
                public ApplicationInfo getApplicationInfo() {
                    ApplicationInfo info = new ApplicationInfo(super.getApplicationInfo());
                    // On Lollipop the condition we need to fail is
                    // "targetSdkVersion >= Build.VERSION_CODES.LOLLIPOP"
                    // (and for Chrome targetSdkVersion is always the latest)
                    info.targetSdkVersion = Build.VERSION_CODES.KITKAT;

                    // On M+ the condition we need to fail is
                    // "flags & ApplicationInfo.FLAG_HARDWARE_ACCELERATED"
                    info.flags &= ~ApplicationInfo.FLAG_HARDWARE_ACCELERATED;
                    return info;
                }
            });

            setView(toast.getView());
        }
        mToast.setGravity(
                mToast.getGravity(), mToast.getXOffset(), mToast.getYOffset() + sExtraYOffset);
    }

    public android.widget.Toast getAndroidToast() {
        return mToast;
    }

    public void show() {
        mToast.show();
    }

    public void cancel() {
        mToast.cancel();
    }

    public void setView(View view) {
        if (mSWLayout != null) {
            mSWLayout.removeAllViews();
            if (view != null) {
                mSWLayout.addView(view, WRAP_CONTENT, WRAP_CONTENT);
                mToast.setView(mSWLayout);
            } else {
                // When null view is set we propagate it to the toast to trigger appropriate
                // handling (for example show() throws an exception when view is null).
                mToast.setView(null);
            }
        } else {
            mToast.setView(view);
        }
    }

    public View getView() {
        if (mToast.getView() == null) {
            return null;
        }
        if (mSWLayout != null) {
            return mSWLayout.getChildAt(0);
        } else {
            return mToast.getView();
        }
    }

    public void setDuration(int duration) {
        mToast.setDuration(duration);
    }

    public int getDuration() {
        return mToast.getDuration();
    }

    public void setMargin(float horizontalMargin, float verticalMargin) {
        mToast.setMargin(horizontalMargin, verticalMargin);
    }

    public float getHorizontalMargin() {
        return mToast.getHorizontalMargin();
    }

    public float getVerticalMargin() {
        return mToast.getVerticalMargin();
    }

    public void setGravity(int gravity, int xOffset, int yOffset) {
        mToast.setGravity(gravity, xOffset, yOffset);
    }

    public int getGravity() {
        return mToast.getGravity();
    }

    public int getXOffset() {
        return mToast.getXOffset();
    }

    public int getYOffset() {
        return mToast.getYOffset();
    }

    public void setText(int resId) {
        mToast.setText(resId);
    }

    public void setText(CharSequence s) {
        mToast.setText(s);
    }

    @SuppressLint("ShowToast")
    public static Toast makeText(Context context, CharSequence text, int duration) {
        return new Toast(context, UiWidgetFactory.getInstance().makeToast(context, text, duration));
    }

    public static Toast makeText(Context context, int resId, int duration)
            throws Resources.NotFoundException {
        return makeText(context, context.getResources().getText(resId), duration);
    }

    /**
     * Set extra Y offset for toasts all toasts created with this class. This can be overridden by
     * calling {@link Toast#setGravity(int, int, int)} on an individual toast.
     * @param yOffsetPx The Y offset from the normal toast position in px.
     */
    public static void setGlobalExtraYOffset(int yOffsetPx) {
        sExtraYOffset = yOffsetPx;
    }

    /**
     * Shows a toast anchored on a view.
     * @param context The context to use for the toast.
     * @param view The view to anchor the toast.
     * @param description The string shown in the toast.
     * @return Whether a toast has been shown successfully.
     */
    @SuppressLint("RtlHardcoded")
    public static boolean showAnchoredToast(Context context, View view, CharSequence description) {
        if (description == null) return false;

        final int screenWidth = context.getResources().getDisplayMetrics().widthPixels;
        final int screenHeight = context.getResources().getDisplayMetrics().heightPixels;
        final int[] screenPos = new int[2];
        view.getLocationOnScreen(screenPos);
        final int width = view.getWidth();
        final int height = view.getHeight();

        final int horizontalGravity =
                (screenPos[0] < screenWidth / 2) ? Gravity.LEFT : Gravity.RIGHT;
        final int xOffset = (screenPos[0] < screenWidth / 2)
                ? screenPos[0] + width / 2
                : screenWidth - screenPos[0] - width / 2;
        final int yOffset = (screenPos[1] < screenHeight / 2) ? screenPos[1] + height / 2
                                                              : screenPos[1] - height * 3 / 2;

        Toast toast = Toast.makeText(context, description, Toast.LENGTH_SHORT);
        toast.setGravity(Gravity.TOP | horizontalGravity, xOffset, yOffset);
        toast.show();
        return true;
    }
}