design/src/android/support/design/internal/SnackbarContentLayout.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 android.support.design.internal;

import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP;

import android.content.Context;
import android.content.res.TypedArray;
import android.support.annotation.RestrictTo;
import android.support.design.R;
import android.support.design.widget.BaseTransientBottomBar;
import android.support.v4.view.ViewCompat;
import android.util.AttributeSet;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

/**
 * @hide
 */
@RestrictTo(LIBRARY_GROUP)
public class SnackbarContentLayout extends LinearLayout implements
        BaseTransientBottomBar.ContentViewCallback {
    private TextView mMessageView;
    private Button mActionView;

    private int mMaxWidth;
    private int mMaxInlineActionWidth;

    public SnackbarContentLayout(Context context) {
        this(context, null);
    }

    public SnackbarContentLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SnackbarLayout);
        mMaxWidth = a.getDimensionPixelSize(R.styleable.SnackbarLayout_android_maxWidth, -1);
        mMaxInlineActionWidth = a.getDimensionPixelSize(
                R.styleable.SnackbarLayout_maxActionInlineWidth, -1);
        a.recycle();
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        mMessageView = (TextView) findViewById(R.id.snackbar_text);
        mActionView = (Button) findViewById(R.id.snackbar_action);
    }

    public TextView getMessageView() {
        return mMessageView;
    }

    public Button getActionView() {
        return mActionView;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        if (mMaxWidth > 0 && getMeasuredWidth() > mMaxWidth) {
            widthMeasureSpec = MeasureSpec.makeMeasureSpec(mMaxWidth, MeasureSpec.EXACTLY);
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }

        final int multiLineVPadding = getResources().getDimensionPixelSize(
                R.dimen.design_snackbar_padding_vertical_2lines);
        final int singleLineVPadding = getResources().getDimensionPixelSize(
                R.dimen.design_snackbar_padding_vertical);
        final boolean isMultiLine = mMessageView.getLayout().getLineCount() > 1;

        boolean remeasure = false;
        if (isMultiLine && mMaxInlineActionWidth > 0
                && mActionView.getMeasuredWidth() > mMaxInlineActionWidth) {
            if (updateViewsWithinLayout(VERTICAL, multiLineVPadding,
                    multiLineVPadding - singleLineVPadding)) {
                remeasure = true;
            }
        } else {
            final int messagePadding = isMultiLine ? multiLineVPadding : singleLineVPadding;
            if (updateViewsWithinLayout(HORIZONTAL, messagePadding, messagePadding)) {
                remeasure = true;
            }
        }

        if (remeasure) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

    private boolean updateViewsWithinLayout(final int orientation,
            final int messagePadTop, final int messagePadBottom) {
        boolean changed = false;
        if (orientation != getOrientation()) {
            setOrientation(orientation);
            changed = true;
        }
        if (mMessageView.getPaddingTop() != messagePadTop
                || mMessageView.getPaddingBottom() != messagePadBottom) {
            updateTopBottomPadding(mMessageView, messagePadTop, messagePadBottom);
            changed = true;
        }
        return changed;
    }

    private static void updateTopBottomPadding(View view, int topPadding, int bottomPadding) {
        if (ViewCompat.isPaddingRelative(view)) {
            ViewCompat.setPaddingRelative(view,
                    ViewCompat.getPaddingStart(view), topPadding,
                    ViewCompat.getPaddingEnd(view), bottomPadding);
        } else {
            view.setPadding(view.getPaddingLeft(), topPadding,
                    view.getPaddingRight(), bottomPadding);
        }
    }

    @Override
    public void animateContentIn(int delay, int duration) {
        mMessageView.setAlpha(0f);
        mMessageView.animate().alpha(1f).setDuration(duration)
                .setStartDelay(delay).start();

        if (mActionView.getVisibility() == VISIBLE) {
            mActionView.setAlpha(0f);
            mActionView.animate().alpha(1f).setDuration(duration)
                    .setStartDelay(delay).start();
        }
    }

    @Override
    public void animateContentOut(int delay, int duration) {
        mMessageView.setAlpha(1f);
        mMessageView.animate().alpha(0f).setDuration(duration)
                .setStartDelay(delay).start();

        if (mActionView.getVisibility() == VISIBLE) {
            mActionView.setAlpha(1f);
            mActionView.animate().alpha(0f).setDuration(duration)
                    .setStartDelay(delay).start();
        }
    }
}