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      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 
     17 package com.android.printspooler.widget;
     18 
     19 import android.content.Context;
     20 import android.graphics.drawable.BitmapDrawable;
     21 import android.graphics.drawable.Drawable;
     22 import android.print.PrintAttributes.MediaSize;
     23 import android.print.PrintAttributes.Margins;
     24 import android.util.AttributeSet;
     25 import android.view.View;
     26 import com.android.printspooler.model.PageContentRepository;
     27 import com.android.printspooler.model.PageContentRepository.RenderSpec;
     28 import 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  */
     36 public 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