JAL-2600 fast painting on resize

[jalview.git] / src / jalview / gui / SeqCanvas.java

diff --git a/src/jalview/gui/SeqCanvas.java b/src/jalview/gui/SeqCanvas.java
index d3ba304..e8f9c5b 100755 (executable)
--- a/src/jalview/gui/SeqCanvas.java
+++ b/src/jalview/gui/SeqCanvas.java
@@ -277,7 +277,7 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
    * @param vertical
    *          shift up or down in repaint
    */
-  public void fastPaint(int horizontal, int vertical)
+  public void fastPaint(int horizontal, int vertical, boolean isresize)
   {
     if (fastpainting || gg == null)
     {
@@ -286,8 +286,6 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
     fastpainting = true;
     fastPaint = true;
     updateViewport();
-    gg.copyArea(horizontal * charWidth, vertical * charHeight, imgWidth,
-            imgHeight, -horizontal * charWidth, -vertical * charHeight);
 
     ViewportRanges ranges = av.getRanges();
     int sr = ranges.getStartRes();
@@ -297,35 +295,60 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
     int transX = 0;
     int transY = 0;
 
-    if (horizontal > 0) // scrollbar pulled right, image to the left
+    if (isresize)
     {
-      transX = (er - sr - horizontal) * charWidth;
-      sr = er - horizontal;
-    }
-    else if (horizontal < 0)
-    {
-      er = sr - horizontal;
+      imgWidth = getWidth();
+      imgHeight = getHeight();
+
+      imgWidth -= (imgWidth % charWidth);
+      imgHeight -= (imgHeight % charHeight);
+
+      BufferedImage newimg = new BufferedImage(imgWidth, imgHeight,
+              BufferedImage.TYPE_INT_ARGB);
+
+      gg = (Graphics2D) newimg.getGraphics();
+      gg.setFont(av.getFont());
+      gg.drawImage(img, null, 0, 0);
+      img = newimg;
+
+      transX = (er - horizontal - sr) * charWidth;
+      sr = er - horizontal - sr;
     }
-    else if (vertical > 0) // scroll down
+    else
     {
-      ss = es - vertical;
+      gg.copyArea(horizontal * charWidth, vertical * charHeight, imgWidth,
+              imgHeight, -horizontal * charWidth, -vertical * charHeight);
 
-      if (ss < ranges.getStartSeq())
-      { // ie scrolling too fast, more than a page at a time
-        ss = ranges.getStartSeq();
+      if (horizontal > 0) // scrollbar pulled right, image to the left
+      {
+        transX = (er - sr - horizontal) * charWidth;
+        sr = er - horizontal;
       }
-      else
+      else if (horizontal < 0)
       {
-        transY = imgHeight - ((vertical + 1) * charHeight);
+        er = sr - horizontal;
       }
-    }
-    else if (vertical < 0)
-    {
-      es = ss - vertical;
+      else if (vertical > 0) // scroll down
+      {
+        ss = es - vertical;
 
-      if (es > ranges.getEndSeq())
+        if (ss < ranges.getStartSeq())
+        { // ie scrolling too fast, more than a page at a time
+          ss = ranges.getStartSeq();
+        }
+        else
+        {
+          transY = imgHeight - ((vertical + 1) * charHeight);
+        }
+      }
+      else if (vertical < 0)
       {
-        es = ranges.getEndSeq();
+        es = ss - vertical;
+
+        if (es > ranges.getEndSeq())
+        {
+          es = ranges.getEndSeq();
+        }
       }
     }
 
@@ -1005,16 +1028,18 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
         {
           scrollX = vpRanges.getStartRes() - vpRanges.getEndRes();
         }
-        fastPaint(scrollX, 0);
+        fastPaint(scrollX, 0, false);
       }
       else if (evt.getPropertyName().equals("endres"))
       {
         // resize - only endres changes
+        int scrollX = (int) evt.getNewValue() - (int) evt.getOldValue();
+        fastPaint(scrollX, 0, true);
       }
       else if (evt.getPropertyName().equals("startseq"))
       {
         // scroll
-        fastPaint(0, (int) evt.getNewValue() - (int) evt.getOldValue());
+        fastPaint(0, (int) evt.getNewValue() - (int) evt.getOldValue(), false);
       }
       else if (evt.getPropertyName().equals("endseq"))
       {