Taking scrolling into account when exporting images. Fixes igvteam#1033

Author: jrobinso

src/main/java/org/broad/igv/ui/panel/DataPanelContainer.java

@@ -138,6 +138,7 @@ public int compare(Component component, Component component1) {
             if (c instanceof DataPanel) {
                 Graphics2D g2d = (Graphics2D) g.create();
                 Rectangle clipRect = new Rectangle(c.getBounds());
+                clipRect.y = rect.y;
                 clipRect.height = rect.height;
                 g2d.setClip(clipRect);
                 g2d.translate(c.getX(), 0);

src/main/java/org/broad/igv/ui/panel/TrackPanel.java

@@ -503,6 +503,7 @@ public void paintOffscreen(Graphics2D g, Rectangle rect, boolean batch) {
         g.translate(mainPanel.getNamePanelX(), 0);
 
         Rectangle nameRect = new Rectangle(children[0].getBounds());
+        nameRect.y = rect.y;
         nameRect.height = h;
         if (nameRect.width > 0) {
             Graphics2D nameGraphics = (Graphics2D) g.create();
@@ -513,7 +514,7 @@ public void paintOffscreen(Graphics2D g, Rectangle rect, boolean batch) {
 
         int dx = mainPanel.getAttributePanelX() - mainPanel.getNamePanelX();
         g.translate(dx, 0);
-        Rectangle attRect = new Rectangle(0, 0, children[1].getWidth(), h);
+        Rectangle attRect = new Rectangle(0, rect.y, children[1].getWidth(), h);
         if (attRect.width > 0) {
             Graphics2D attGraphics = (Graphics2D) g.create();
             attGraphics.setClip(attRect);
@@ -523,7 +524,7 @@ public void paintOffscreen(Graphics2D g, Rectangle rect, boolean batch) {
 
         dx = mainPanel.getDataPanelX() - mainPanel.getAttributePanelX();
         g.translate(dx, 0);
-        Rectangle dataRect = new Rectangle(0, 0, mainPanel.getDataPanelWidth(), h);
+        Rectangle dataRect = new Rectangle(0, rect.y, mainPanel.getDataPanelWidth(), h);
         Graphics2D dataGraphics = (Graphics2D) g.create();
         dataGraphics.setClip(dataRect);
         ((Paintable) children[2]).paintOffscreen(dataGraphics, dataRect, batch);

src/main/java/org/broad/igv/ui/panel/TrackPanelScrollPane.java

@@ -127,6 +127,9 @@ public TrackNamePanel getNamePanel() {
 
     @Override
     public void paintOffscreen(Graphics2D g, Rectangle tspRect, boolean batch) {
+        int yOffset = getViewport().getViewPosition().y;
+        tspRect.y = yOffset;
+        g.translate(0, -yOffset);
         trackPanel.paintOffscreen(g, tspRect, batch);
     }