First draft of "navigator", a strip of "live" thumbnails which are clickable.

Open method to open random page, not first.
Put some UI set up in documentLoadTask as the UI requires the number of pages in the document which is only know on load.

android/experimental/LibreOffice4Android/res/layout/document_viewer.xml

@@ -13,11 +13,13 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
 		android:layout_alignBottom="@id/page_flipper"
+		android:scrollbarAlwaysDrawHorizontalTrack="true"
 		android:background="#aa000000">
 		<LinearLayout
 	   	    android:id="@+id/navigator"
 		    android:layout_width="wrap_content"
-		    android:layout_height="150dp"
+		    android:layout_height="120dp"
+		    android:layout_margin="15dp"
 		    android:orientation="horizontal">
 		</LinearLayout>
 	</HorizontalScrollView >

android/experimental/LibreOffice4Android/src/org/libreoffice/android/DocumentLoader.java

@@ -95,7 +95,7 @@ public class DocumentLoader
     extends Activity
 {
     private static final String TAG = "DocumentLoader";
-
+    
     // Size of a small virtual (bitmap) device used to find out page count and
     // page sizes
     private static final int SMALLSIZE = 128;
@@ -152,7 +152,7 @@ public class DocumentLoader
                 flipper.setOutAnimation(outToLeft);
 
                 flipper.showNext();
-
+                
                 ((PageViewer)flipper.getChildAt((flipper.getDisplayedChild() + PAGECACHE_PLUSMINUS) % PAGECACHE_SIZE)).display(((PageViewer)flipper.getCurrentView()).currentPageNumber + PAGECACHE_PLUSMINUS);
                 return true;
             } else if (event2.getX() - event1.getX() > 120) {
@@ -523,7 +523,13 @@ public class DocumentLoader
         View thumbnailView;
         //PageState state = PageState.NONEXISTENT;
         Bitmap bm;
-
+        final float scale;
+        final int widthInPx;
+        final int heightInPx;
+        final int defaultWidthPx = 120;
+        final int defaultHeightPx = 120;
+        final int thumbnailPaddingDp = 10;
+        		
         class ThumbLoadTask
             extends AsyncTask<Integer, Void, Integer>
         {
@@ -535,8 +541,8 @@ public class DocumentLoader
                     return -1;
 
                 //state = PageState.LOADING;
-                ByteBuffer bb = renderPage( number , 120 , 120);
-                bm = Bitmap.createBitmap( 120 , 120 , Bitmap.Config.ARGB_8888);
+                ByteBuffer bb = renderPage( number , widthInPx , heightInPx);
+                bm = Bitmap.createBitmap( widthInPx , heightInPx , Bitmap.Config.ARGB_8888);
                 bm.copyPixelsFromBuffer(bb);
 
                 return number;
@@ -552,7 +558,8 @@ public class DocumentLoader
                 
 				ImageView thumbImage = new ImageView(DocumentLoader.this);//(ImageView)findViewById( R.id.thumbnail );
                 thumbImage.setImageBitmap(bm);
-
+                int paddingPx = (int) (thumbnailPaddingDp* scale + 0.5f);
+                thumbImage.setPadding( paddingPx , 0 , paddingPx , 0 );
                 thumbImage.setScaleY(-1);
 
 				Log.i( TAG, Integer.toString( thumbImage.getWidth() ) );
@@ -570,15 +577,31 @@ public class DocumentLoader
             if (number >= 0)
                 waitView.setText("Page " + (number+1) + ", wait...");
             //state = PageState.NONEXISTENT;
-
             if (number >= 0) {
                 new ThumbLoadTask().executeOnExecutor(AsyncTask.SERIAL_EXECUTOR, number);
             }
         }
 
+        ThumbnailView(int number , int widthInDp , int heightInDp)
+        {
+            super(DocumentLoader.this);
+            scale = getContext().getResources().getDisplayMetrics().density;
+            widthInPx = (int) (widthInDp * scale + 0.5f);
+            heightInPx = (int) (heightInDp* scale + 0.5f);
+			waitView = new TextView( DocumentLoader.this );
+            thumbnailView = inflater.inflate( R.layout.navigation_grid_item , null);
+
+            display(number);
+            
+            
+        }
+        
         ThumbnailView(int number)
         {
             super(DocumentLoader.this);
+            scale = getContext().getResources().getDisplayMetrics().density;
+            widthInPx = defaultWidthPx;
+            heightInPx = defaultHeightPx;
 			waitView = new TextView( DocumentLoader.this );
             thumbnailView = inflater.inflate( R.layout.navigation_grid_item , null);
 
@@ -589,9 +612,21 @@ public class DocumentLoader
     }
 
     class DocumentLoadTask
-        extends AsyncTask<String, Void, Void>
+        extends AsyncTask<String, Void, Integer>
     {
-        protected Void doInBackground(String... params)
+    	protected void onPreExecute (){
+    		TextView waitView = new TextView(DocumentLoader.this);
+            waitView.setTextSize(24);
+            waitView.setGravity(Gravity.CENTER);
+            waitView.setBackgroundColor(Color.WHITE);
+            waitView.setTextColor(Color.BLACK);
+    		waitView.setText("Page " + (1) + ", wait...");
+    		flipper = new ViewFlipper(DocumentLoader.this);
+			flipper = (ViewFlipper)findViewById( R.id.page_flipper );
+            matchParent = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
+            flipper.addView( waitView , 0 , matchParent);
+    	}
+        protected Integer doInBackground(String... params)
         {
             try {
                 String url = params[0];
@@ -645,7 +680,46 @@ public class DocumentLoader
                 e.printStackTrace(System.err);
                 finish();
             }
-            return null;
+            return new Integer( pageCount );
+        }
+    
+        protected void onPostExecute(Integer result){
+        	Log.i(TAG, "onPostExecute: " + result);
+            if (result == -1)
+                return;
+          //flipper = new ViewFlipper(this);
+			flipper = (ViewFlipper)findViewById( R.id.page_flipper );
+            matchParent = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
+
+            flipper.removeViewAt( 0 );	
+            
+            //Should check that pages exist ie >=0 && < pageCount
+            flipper.addView(new PageViewer(0), 0, matchParent);
+            for (int i = 0; i < PAGECACHE_PLUSMINUS; i++)
+                flipper.addView(new PageViewer(i+1), i+1, matchParent);
+            for (int i = 0; i < PAGECACHE_PLUSMINUS; i++)
+                flipper.addView(new PageViewer(-1), PAGECACHE_PLUSMINUS + i+1, matchParent);
+                
+            ll = (LinearLayout)findViewById( R.id.navigator);
+            inflater = (LayoutInflater) getApplicationContext().getSystemService(
+				Context.LAYOUT_INFLATER_SERVICE);
+
+			
+			
+			for( int i = 0; i < result.intValue() ; i++ ){
+				ThumbnailView thumb = new ThumbnailView( i , (int)(120.0f / Math.sqrt(2) ) , 120 );
+				final int pos = i;
+				thumb.setOnClickListener(new OnClickListener() {
+			
+					@Override
+					public void onClick(View v) {
+						// TODO Auto-generated method stub
+						Log.d("nav" , Integer.toString( pos ) );
+						openPageWithPrefetching( pos );
+					}
+				});
+				ll.addView ( thumb );
+			}
         }
     }
 
@@ -771,14 +845,18 @@ public class DocumentLoader
 
             Log.i(TAG, "componentLoader is" + (componentLoader!=null ? " not" : "") + " null");
 
+            setContentView( R.layout.document_viewer );
             // Load the wanted document
             new DocumentLoadTask().executeOnExecutor(AsyncTask.SERIAL_EXECUTOR, "file://" + input);
 
-			setContentView( R.layout.document_viewer );
+			/*
             //flipper = new ViewFlipper(this);
 			flipper = (ViewFlipper)findViewById( R.id.page_flipper );
             matchParent = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
 
+            // should have document load task publish pageCount before this happens: Shouldn't try to pre-fetch
+            // non-existant pages && need to know how many navigation thumbnails to render.
+            // Should put these on anothe serial executor?
             flipper.addView(new PageViewer(0), 0, matchParent);
             for (int i = 0; i < PAGECACHE_PLUSMINUS; i++)
                 flipper.addView(new PageViewer(i+1), i+1, matchParent);
@@ -788,20 +866,11 @@ public class DocumentLoader
             ll = (LinearLayout)findViewById( R.id.navigator);
             inflater = (LayoutInflater) getApplicationContext().getSystemService(
 				Context.LAYOUT_INFLATER_SERVICE);
-            
-			
-			
-			//ThumbnailView pv = new ThumbnailView(0);
-            /*Bitmap thumbnailBitmap = Bitmap.createBitmap(120, 120, Bitmap.Config.ARGB_8888);
-            thumbnailBitmap.copyPixelsFromBuffer(bb);
-            ImageView pageImage = (ImageView)findViewById( R.id.thumbnail );
-            pageImage.setImageBitmap( thumbnailBitmap );
-			*/
+
 			
 			
 			for( int i = 0; i < 2 ; i++ ){
-				View thumbnailView = inflater.inflate( R.layout.navigation_grid_item , null );
-				ThumbnailView thumb = new ThumbnailView( i );
+				ThumbnailView thumb = new ThumbnailView( i , (int)(120.0f / Math.sqrt(2) ) , 120 );
 				final int pos = i;
 				thumb.setOnClickListener(new OnClickListener() {
 			
@@ -809,11 +878,11 @@ public class DocumentLoader
 					public void onClick(View v) {
 						// TODO Auto-generated method stub
 						Log.d("nav" , Integer.toString( pos ) );
-						//(PageViewer)flipper.getChildAt( (flipper.getDisplayedChild() + PAGECACHE_PLUSMINUS) % PAGECACHE_SIZE)).display( ( (PageViewer)flipper.getCurrentView() ).currentPageNumber + PAGECACHE_PLUSMINUS);
+						
 					}
 				});
 				ll.addView ( thumb );
-			}
+			}*/
             
 	    	
         }
@@ -843,6 +912,26 @@ public class DocumentLoader
 	            return super.onOptionsItemSelected(item);
 	    }
 	}
+    
+    /* if page is more than 2*+- away then no cache over lap
+     * load page && fill cache
+     * if page is */
+    public void openPageWithPrefetching( int number ){
+    	//as a first draft clear an refill "cache" on load.
+    	//should move views where "cache window" overlaps 
+    	flipper.removeAllViews();
+    	flipper.addView(new PageViewer(number), 0, matchParent);
+        for (int i = 0; i < PAGECACHE_PLUSMINUS; i++){
+        	if( number + i+1 >= 0 && number + i+1 < pageCount){//pageCount will always be correctly defined when this is called (famous last words)
+        		flipper.addView(new PageViewer( number + i+1), i+1, matchParent);
+        	}
+        }
+        for (int i = 0; i < PAGECACHE_PLUSMINUS; i++){
+        	if( number + i+1 >= 0 && number + i+1 < pageCount){
+                flipper.addView(new PageViewer( number - (i+1)), PAGECACHE_PLUSMINUS + i+1, matchParent);
+        	}
+        }
+    }
 }
 
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