deal with page down exception, fixes #2990

app/src/processing/app/syntax/InputHandler.java

@@ -864,21 +864,24 @@ public abstract class InputHandler extends KeyAdapter
                         int visibleLines = textArea.getVisibleLines();
                         int line = textArea.getCaretLine();
 
-                        firstLine += visibleLines;
-                        if (firstLine >= lineCount )
-                          firstLine -= visibleLines;
-                        else if(firstLine + visibleLines >= lineCount - 1)
-                          firstLine = lineCount - visibleLines;
+                        // Can't page down if there's nothing to visit
+                        // https://github.com/processing/processing/issues/2990
+                        if (lineCount > visibleLines) {                        
+                          firstLine += visibleLines;  // page down
+                          if (firstLine + visibleLines >= lineCount - 1) {
+                            // back up to the latest line we can go to 
+                            firstLine = lineCount - visibleLines;
+                          }
+                        
 
-                        textArea.setFirstLine(firstLine);
+                          textArea.setFirstLine(firstLine);
 
-                        int caret = textArea.getLineStartOffset(
-                                Math.min(textArea.getLineCount() - 1,
-                                line + visibleLines));
-                        if(select)
-                                textArea.select(textArea.getMarkPosition(),caret);
-                        else
-                                textArea.setCaretPosition(caret);
+                          int caret = textArea.getLineStartOffset(Math.min(textArea.getLineCount() - 1, line + visibleLines));
+                          if (select)
+                            textArea.select(textArea.getMarkPosition(),caret);
+                          else
+                            textArea.setCaretPosition(caret);
+                        }                        
                 }
         }
 

todo.txt

@@ -10,14 +10,10 @@ X   https://github.com/processing/processing/issues/3014
 X add more bulletproofing to the save process
 X   https://github.com/processing/processing/issues/2923
 X serious text improvements (at least on retina)
-_ finish adding 'examples' contribs
-_   https://github.com/processing/processing/issues/2953
-_   don't return here, allow contrib types to fail:
-_   https://github.com/processing/processing/blob/master/app/src/processing/app/contrib/ContributionListing.java#L509
-_ trying to add a second tab with the same name causes an error
-
-_ Opening and closing preferences window prompts user to save unmodified sketch
-_   https://github.com/processing/processing/issues/3074
+X Menu mnemonics (alt-f, etc) getting typed into the editor
+X   https://github.com/processing/processing/issues/3057
+X Opening and closing preferences window prompts user to save unmodified sketch
+X   https://github.com/processing/processing/issues/3074
 
 _ implement line numbers in the editor
 _   5px between line number (right-aligned) and the right edge of the gutter
@@ -33,6 +29,8 @@ _   two new fonts have been added, other languages will need more
 _   need a decent sans with with Unicode coverage
 _   i.e. https://github.com/processing/processing/pull/3025
 
+_ trying to add a second tab with the same name causes an error
+
 jre download/install
 X make sure the file downloads correctly before renaming
 X   https://github.com/processing/processing/issues/2960
@@ -86,6 +84,9 @@ X   https://github.com/processing/processing/issues/2566
 X make fatal errors terminate the pde
 X   https://github.com/processing/processing/issues/3068
 X   https://github.com/processing/processing/pull/3069
+X Java 8 method replace() used, removed
+X   https://github.com/processing/processing/issues/3168
+X   https://github.com/processing/processing/pull/3169
 
 manindra
 X Fix for "Probably a ++ should go here" messages
@@ -176,6 +177,12 @@ _ crashed on startup w/ JavaScript mode as default b/c PdeKeyListener not found
 _   because it's in the other ClassLoader, can no longer rely on it
 _ remove JavaMode.errorLogsEnabled and JavaEditor.writeErrorsToFile()
 
+3.0a7
+_ finish adding 'examples' contribs
+_   https://github.com/processing/processing/issues/2953
+_   don't return here, allow contrib types to fail:
+_   https://github.com/processing/processing/blob/master/app/src/processing/app/contrib/ContributionListing.java#L509
+
 _ disable the debug toggle menu while running
 _   otherwise could run in one mode, then try to stop in another
 _ show debug window when running, hide when stopped