Bugzilla – Full Text Bug Listing
| Summary: | ScrollBar figure get created although the Pane set the scroll bar visibilty to NEVER | ||
|---|---|---|---|
| Product: | [Tools] GEF | Reporter: | Mohammed Mostafa <mmostafa> |
| Component: | GEF-Legacy Draw2d | Assignee: | gef-inbox <gef-inbox> |
| Status: | RESOLVED WORKSFORME | QA Contact: | |
| Severity: | normal | ||
| Priority: | P3 | CC: | nyssen |
| Version: | unspecified | ||
| Target Milestone: | --- | ||
| Hardware: | PC | ||
| OS: | Windows XP | ||
| Whiteboard: | |||
The change is to avoid calling a method so that lazy creation doesn't occur? The change sounds fine to me, but I don't expect huge savings in memory usage. Subclasses have access to the protected fields directly, so some clients might expect the fields to not be NULL, perhaps when painting or something. Changing this in the maintenance stream might break working client code. I think it would be cleaner to not return a scrollbar within scrollpane if there is no scrollbar. However, this would be an API-incompatible change. Due to this and the fact that there are protected fields involved (as Randy pointed out), resolving as WORKSFORME. |
The fact that the ScrollPaneLayout#layout method do ScrollBar hBar = scrollpane.getHorizontalScrollBar(), vBar = scrollpane.getVerticalScrollBar(); in line 86 and 87, means that the Vscroll bar and the Horizontal scroll bar wil be created regardless of the fact that the HorizontalScrollBarVisibility or the VerticalScrollBarVisibility might be set to NEVER If the implementation of this method is changed to look like this ScrollPane scrollpane = (ScrollPane) parent; Rectangle clientArea = parent.getClientArea(); int bottom = 0; int right = 0 ; int hVis = scrollpane.getHorizontalScrollBarVisibility(), vVis = scrollpane.getVerticalScrollBarVisibility(); Viewport viewport = scrollpane.getViewport(); Dimension available = clientArea.getSize(); Dimension preferred = viewport.getPreferredSize(available.width, available.height).getCopy(); boolean none = available.contains(preferred); boolean both = !none && vVis != NEVER && hVis != NEVER && preferred.contains(available); boolean showV = both || preferred.height > available.height; boolean showH = both || preferred.width > available.width; //Adjust for visibility override flags showV = !(vVis == NEVER) && (showV || vVis == ALWAYS); showH = !(hVis == NEVER) && (showH || hVis == ALWAYS); Rectangle bounds, viewportArea = clientArea; int hPad = 0; int vPad = 0; ScrollBar vBar = null; ScrollBar hBar = null; if (hVis!=NEVER) hBar = scrollpane.getHorizontalScrollBar(); if (vVis!=NEVER) vBar = scrollpane.getVerticalScrollBar(); if (showH){ bottom = hBar.getPreferredSize(clientArea.width, clientArea.height).height; hPad = hBar.getSize().height; } if (showV){ right = vBar.getPreferredSize(clientArea.width, clientArea.height).width; vPad = vBar.getSize().width; } if (showV) { bounds = new Rectangle( viewportArea.right() - right, viewportArea.y, right, viewportArea.height - hPad); vBar.setBounds(bounds); } if (showH) { bounds = new Rectangle( viewportArea.x, viewportArea.bottom() - bottom, viewportArea.width - vPad, bottom); hBar.setBounds(bounds); } if (vBar!=null) vBar.setVisible(showV); if (hBar!=null) hBar.setVisible(showH); viewport.setBounds(viewportArea); Then the Scroll bars with Visibility set to never will not be created