https://github.com/TalbotGooday/AndroidPdfViewer/issues/1

Author: TalbotGooday

android-pdf-viewer/src/main/java/com/github/barteksc/pdfviewer/PDFView.java

@@ -114,18 +114,26 @@ enum ScrollDir {
 
     private ScrollDir scrollDir = ScrollDir.NONE;
 
-    /** Rendered parts go to the cache manager */
+    /**
+     * Rendered parts go to the cache manager
+     */
     CacheManager cacheManager;
 
-    /** Animation manager manage all offset and zoom animation */
+    /**
+     * Animation manager manage all offset and zoom animation
+     */
     private AnimationManager animationManager;
 
-    /** Drag manager manage all touch events */
+    /**
+     * Drag manager manage all touch events
+     */
     private DragPinchManager dragPinchManager;
 
     PdfFile pdfFile;
 
-    /** The index of the current sequence */
+    /**
+     * The index of the current sequence
+     */
     private int currentPage;
 
     /**
@@ -142,41 +150,61 @@ enum ScrollDir {
      */
     private float currentYOffset = 0;
 
-    /** The zoom level, always >= 1 */
+    /**
+     * The zoom level, always >= 1
+     */
     private float zoom = 1f;
 
-    /** True if the PDFView has been recycled */
+    /**
+     * True if the PDFView has been recycled
+     */
     private boolean recycled = true;
 
-    /** Current state of the view */
+    /**
+     * Current state of the view
+     */
     private State state = State.DEFAULT;
 
-    /** Async task used during the loading phase to decode a PDF document */
+    /**
+     * Async task used during the loading phase to decode a PDF document
+     */
     private DecodingAsyncTask decodingAsyncTask;
 
-    /** The thread {@link #renderingHandler} will run on */
+    /**
+     * The thread {@link #renderingHandler} will run on
+     */
     private HandlerThread renderingHandlerThread;
-    /** Handler always waiting in the background and rendering tasks */
+    /**
+     * Handler always waiting in the background and rendering tasks
+     */
     RenderingHandler renderingHandler;
 
     private PagesLoader pagesLoader;
 
     Callbacks callbacks = new Callbacks();
 
-    /** Paint object for drawing */
+    /**
+     * Paint object for drawing
+     */
     private Paint paint;
 
-    /** Paint object for drawing debug stuff */
+    /**
+     * Paint object for drawing debug stuff
+     */
     private Paint debugPaint;
 
-    /** Policy for fitting pages to screen */
+    /**
+     * Policy for fitting pages to screen
+     */
     private FitPolicy pageFitPolicy = FitPolicy.WIDTH;
 
     private boolean fitEachPage = false;
 
     private int defaultPage = 0;
 
-    /** True if should scroll through pages vertically instead of horizontally */
+    /**
+     * True if should scroll through pages vertically instead of horizontally
+     */
     private boolean swipeVertical = true;
 
     private boolean enableSwipe = true;
@@ -187,7 +215,9 @@ enum ScrollDir {
 
     private boolean pageSnap = true;
 
-    /** Pdfium core for loading and rendering PDFs */
+    /**
+     * Pdfium core for loading and rendering PDFs
+     */
     private PdfiumCore pdfiumCore;
 
     private ScrollHandle scrollHandle;
@@ -218,30 +248,46 @@ ScrollHandle getScrollHandle() {
      */
     private boolean renderDuringScale = false;
 
-    /** Antialiasing and bitmap filtering */
+    /**
+     * Antialiasing and bitmap filtering
+     */
     private boolean enableAntialiasing = true;
     private PaintFlagsDrawFilter antialiasFilter =
             new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
 
-    /** Spacing between pages, in px */
+    /**
+     * Spacing between pages, in px
+     */
     private int spacingPx = 0;
 
-    /** Add dynamic spacing to fit each page separately on the screen. */
+    /**
+     * Add dynamic spacing to fit each page separately on the screen.
+     */
     private boolean autoSpacing = false;
 
-    /** Fling a single page at a time */
+    /**
+     * Fling a single page at a time
+     */
     private boolean pageFling = true;
 
-    /** Pages numbers used when calling onDrawAllListener */
+    /**
+     * Pages numbers used when calling onDrawAllListener
+     */
     private List<Integer> onDrawPagesNums = new ArrayList<>(10);
 
-    /** Holds info whether view has been added to layout and has width and height */
+    /**
+     * Holds info whether view has been added to layout and has width and height
+     */
     private boolean hasSize = false;
 
-    /** Holds last used Configurator that should be loaded when view has size */
+    /**
+     * Holds last used Configurator that should be loaded when view has size
+     */
     private Configurator waitingDocumentConfigurator;
 
-    /** Construct the initial view */
+    /**
+     * Construct the initial view
+     */
     public PDFView(Context context, AttributeSet set) {
         super(context, set);
 
@@ -452,7 +498,9 @@ public boolean isRecycled() {
         return recycled;
     }
 
-    /** Handle fling animation */
+    /**
+     * Handle fling animation
+     */
     @Override
     public void computeScroll() {
         super.computeScroll();
@@ -493,10 +541,10 @@ protected void onSizeChanged(int w, int h, int oldw, int oldh) {
         float relativeCenterPointInStripXOffset;
         float relativeCenterPointInStripYOffset;
 
-        if (swipeVertical){
+        if (swipeVertical) {
             relativeCenterPointInStripXOffset = centerPointInStripXOffset / pdfFile.getMaxPageWidth();
             relativeCenterPointInStripYOffset = centerPointInStripYOffset / pdfFile.getDocLen(zoom);
-        }else {
+        } else {
             relativeCenterPointInStripXOffset = centerPointInStripXOffset / pdfFile.getDocLen(zoom);
             relativeCenterPointInStripYOffset = centerPointInStripYOffset / pdfFile.getMaxPageHeight();
         }
@@ -506,12 +554,12 @@ protected void onSizeChanged(int w, int h, int oldw, int oldh) {
 
         if (swipeVertical) {
             currentXOffset = -relativeCenterPointInStripXOffset * pdfFile.getMaxPageWidth() + w * 0.5f;
-            currentYOffset = -relativeCenterPointInStripYOffset * pdfFile.getDocLen(zoom) + h * 0.5f ;
-        }else {
+            currentYOffset = -relativeCenterPointInStripYOffset * pdfFile.getDocLen(zoom) + h * 0.5f;
+        } else {
             currentXOffset = -relativeCenterPointInStripXOffset * pdfFile.getDocLen(zoom) + w * 0.5f;
             currentYOffset = -relativeCenterPointInStripYOffset * pdfFile.getMaxPageHeight() + h * 0.5f;
         }
-        moveTo(currentXOffset,currentYOffset);
+        moveTo(currentXOffset, currentYOffset);
         loadPageByOffset();
     }
 
@@ -667,7 +715,9 @@ private void drawWithListener(Canvas canvas, int page, OnDrawListener listener)
         }
     }
 
-    /** Draw a given PagePart on the canvas */
+    /**
+     * Draw a given PagePart on the canvas
+     */
     private void drawPart(Canvas canvas, PagePart part) {
         // Can seem strange, but avoid lot of calls
         RectF pageRelativeBounds = part.getPageRelativeBounds();
@@ -747,15 +797,22 @@ public void loadPages() {
         redraw();
     }
 
-    /** Called when the PDF is loaded */
+    /**
+     * Called when the PDF is loaded
+     */
     void loadComplete(PdfFile pdfFile) {
         state = State.LOADED;
 
         this.pdfFile = pdfFile;
 
+        if (renderingHandlerThread == null) {
+            return;
+        }
+
         if (!renderingHandlerThread.isAlive()) {
             renderingHandlerThread.start();
         }
+
         renderingHandler = new RenderingHandler(renderingHandlerThread.getLooper(), this);
         renderingHandler.start();
 
@@ -1263,56 +1320,74 @@ public boolean doRenderDuringScale() {
         return renderDuringScale;
     }
 
-    /** Returns null if document is not loaded */
+    /**
+     * Returns null if document is not loaded
+     */
     public PdfDocument.Meta getDocumentMeta() {
         if (pdfFile == null) {
             return null;
         }
         return pdfFile.getMetaData();
     }
 
-    /** Will be empty until document is loaded */
+    /**
+     * Will be empty until document is loaded
+     */
     public List<PdfDocument.Bookmark> getTableOfContents() {
         if (pdfFile == null) {
             return Collections.emptyList();
         }
         return pdfFile.getBookmarks();
     }
 
-    /** Will be empty until document is loaded */
+    /**
+     * Will be empty until document is loaded
+     */
     public List<PdfDocument.Link> getLinks(int page) {
         if (pdfFile == null) {
             return Collections.emptyList();
         }
         return pdfFile.getPageLinks(page);
     }
 
-    /** Use an asset file as the pdf source */
+    /**
+     * Use an asset file as the pdf source
+     */
     public Configurator fromAsset(String assetName) {
         return new Configurator(new AssetSource(assetName));
     }
 
-    /** Use a file as the pdf source */
+    /**
+     * Use a file as the pdf source
+     */
     public Configurator fromFile(File file) {
         return new Configurator(new FileSource(file));
     }
 
-    /** Use URI as the pdf source, for use with content providers */
+    /**
+     * Use URI as the pdf source, for use with content providers
+     */
     public Configurator fromUri(Uri uri) {
         return new Configurator(new UriSource(uri));
     }
 
-    /** Use bytearray as the pdf source, documents is not saved */
+    /**
+     * Use bytearray as the pdf source, documents is not saved
+     */
     public Configurator fromBytes(byte[] bytes) {
         return new Configurator(new ByteArraySource(bytes));
     }
 
-    /** Use stream as the pdf source. Stream will be written to bytearray, because native code does not support Java Streams */
+    /**
+     * Use stream as the pdf source. Stream will be written to bytearray, because native code does not support Java Streams
+     */
     public Configurator fromStream(InputStream stream) {
         return new Configurator(new InputStreamSource(stream));
     }
 
-    /** Use custom source as pdf source */
+    /**
+     * Use custom source as pdf source
+     */
     public Configurator fromSource(DocumentSource docSource) {
         return new Configurator(docSource);
     }