Page Key Navigation in Disassembly (Fix #167)

src/widgets/DisassemblyWidget.cpp

@@ -454,10 +454,43 @@ void DisassemblyWidget::moveCursorRelative(bool up, bool page)
 {
     if (page)
     {
-        // TODO: implement page up/down
+        RVA offset;
-        return;
+        if (!up)
+        {
+            offset = Core()->nextOpAddr(bottomOffset, 1);
+        }
+        else
+        {
+            offset = Core()->prevOpAddr(topOffset, maxLines);
+
+            // disassembly from calculated offset may have more than maxLines lines
+            // move some instructions down if necessary.
+
+            auto lines = Core()->disassembleLines(offset, maxLines).toVector();
+            int oldTopLine;
+            for (oldTopLine=lines.length(); oldTopLine>0; oldTopLine--)
+            {
+                if (lines[oldTopLine - 1].offset < topOffset)
+                {
+                    break;
+                }
             }
 
+            int overflowLines = oldTopLine - maxLines;
+            if(overflowLines > 0)
+            {
+                while (lines[overflowLines-1].offset == lines[overflowLines].offset
+                       && overflowLines < lines.length()-1)
+                {
+                    overflowLines++;
+                }
+                offset = lines[overflowLines].offset;
+            }
+        }
+        refreshDisasm(offset);
+    }
+    else // normal arrow keys
+    {
         int blockCount = mDisasTextEdit->blockCount();
         if (blockCount < 1)
         {
@@ -484,6 +517,7 @@ void DisassemblyWidget::moveCursorRelative(bool up, bool page)
             Core()->seek(offset);
             highlightCurrentLine();
         }
+    }
 }
 
 bool DisassemblyWidget::eventFilter(QObject *obj, QEvent *event)