PageContentView.java revision 066bf81b983ce23b91d19b85b7c37a61fba7a9a6 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.printspooler.widget;
18
19import android.content.Context;
20import android.graphics.drawable.BitmapDrawable;
21import android.graphics.drawable.Drawable;
22import android.print.PrintAttributes.MediaSize;
23import android.print.PrintAttributes.Margins;
24import android.util.AttributeSet;
25import android.view.View;
26import com.android.printspooler.model.PageContentRepository;
27import com.android.printspooler.model.PageContentRepository.RenderSpec;
28import com.android.printspooler.model.PageContentRepository.PageContentProvider;
29
30/**
31 * This class represents a page in the print preview list. The width of the page
32 * is determined by stretching it to take maximal horizontal space while the height
33 * is computed from the width using the page aspect ratio. Note that different media
34 * sizes have different aspect ratios.
35 */
36public class PageContentView extends View
37        implements PageContentRepository.OnPageContentAvailableCallback {
38
39    private PageContentProvider mProvider;
40
41    private MediaSize mMediaSize;
42
43    private Margins mMinMargins;
44
45    private Drawable mEmptyState;
46
47    private Drawable mErrorState;
48
49    private boolean mContentRequested;
50
51    private boolean mIsFailed;
52
53    public PageContentView(Context context, AttributeSet attrs) {
54        super(context, attrs);
55    }
56
57    @Override
58    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
59        mContentRequested = false;
60
61        requestPageContentIfNeeded();
62    }
63
64    @Override
65    public void onPageContentAvailable(BitmapDrawable renderedPage) {
66        mIsFailed = (renderedPage == null);
67
68        if (mIsFailed) {
69            setBackground(mErrorState);
70        } else {
71            setBackground(renderedPage);
72        }
73    }
74
75    public PageContentProvider getPageContentProvider() {
76        return mProvider;
77    }
78
79    public void init(PageContentProvider provider, Drawable emptyState, Drawable errorState,
80            MediaSize mediaSize, Margins minMargins) {
81        final boolean providerChanged = (mProvider == null)
82                ? provider != null : !mProvider.equals(provider);
83        final boolean loadingDrawableChanged = (mEmptyState == null)
84                ? emptyState != null : !mEmptyState.equals(emptyState);
85        final boolean mediaSizeChanged = (mMediaSize == null)
86                ? mediaSize != null : !mMediaSize.equals(mediaSize);
87        final boolean marginsChanged = (mMinMargins == null)
88                ? minMargins != null : !mMinMargins.equals(minMargins);
89
90        if (!providerChanged && !mediaSizeChanged
91                && !marginsChanged && !loadingDrawableChanged) {
92            return;
93        }
94
95        mIsFailed = false;
96        mProvider = provider;
97        mMediaSize = mediaSize;
98        mMinMargins = minMargins;
99
100        mEmptyState = emptyState;
101        mErrorState = errorState;
102        mContentRequested = false;
103
104        // If there is no provider we want immediately to switch to
105        // the empty state, so pages with no content appear blank.
106        if (mProvider == null) {
107            setBackground(mEmptyState);
108        } else if (mIsFailed) {
109            setBackground(mErrorState);
110        }
111
112        requestPageContentIfNeeded();
113    }
114
115    private void requestPageContentIfNeeded() {
116        if (getWidth() > 0 && getHeight() > 0 && !mContentRequested
117                && mProvider != null) {
118            mContentRequested = true;
119            mProvider.getPageContent(new RenderSpec(getWidth(), getHeight(),
120                    mMediaSize, mMinMargins), this);
121        }
122    }
123}
124