packages/SystemUI/src/com/android/systemui/statusbar/notification/TextViewTransformState.java

/*
 * Copyright (C) 2016 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.systemui.statusbar.notification;

import android.text.Layout;
import android.text.TextUtils;
import android.util.Pools;
import android.view.View;
import android.widget.TextView;

/**
 * A transform state of a mText view.
*/
public class TextViewTransformState extends TransformState {

    private static Pools.SimplePool<TextViewTransformState> sInstancePool
            = new Pools.SimplePool<>(40);
    private TextView mText;

    @Override
    public void initFrom(View view) {
        super.initFrom(view);
        if (view instanceof TextView) {
            mText = (TextView) view;
        }
    }

    @Override
    protected boolean sameAs(TransformState otherState) {
        if (super.sameAs(otherState)) {
            return true;
        }
        if (otherState instanceof TextViewTransformState) {
            TextViewTransformState otherTvs = (TextViewTransformState) otherState;
            if(TextUtils.equals(otherTvs.mText.getText(), mText.getText())) {
                int ownEllipsized = getEllipsisCount();
                int otherEllipsized = otherTvs.getEllipsisCount();
                return ownEllipsized == otherEllipsized
                        && getInnerHeight(mText) == getInnerHeight(otherTvs.mText);
            }
        }
        return false;
    }

    private int getInnerHeight(TextView text) {
        return text.getHeight() - text.getPaddingTop() - text.getPaddingBottom();
    }

    private int getEllipsisCount() {
        Layout l = mText.getLayout();
        if (l != null) {
            int lines = l.getLineCount();
            if (lines > 0) {
                // we only care about the first line
                return l.getEllipsisCount(0);
            }
        }
        return 0;
    }

    public static TextViewTransformState obtain() {
        TextViewTransformState instance = sInstancePool.acquire();
        if (instance != null) {
            return instance;
        }
        return new TextViewTransformState();
    }

    @Override
    public void recycle() {
        super.recycle();
        sInstancePool.release(this);
    }

    @Override
    protected void reset() {
        super.reset();
        mText = null;
    }
}