[svn] 4694: Don't remove text lines from the container if it isn' t the container the lines were added to.

Question

Revision: 4694
Author: [email protected]
Date: 2009-01-27 14:35:21 -0800 (Tue, 27 Jan 2009)
Log Message:
Don't remove text lines from the container if it isn't the container the lines were added to. When there is a state change the displayObject can be switched out from under the TextGraphic and TextBox.
QE Notes: need to add tests - will attach my test program to bug
Doc Notes:
Bugs: SDK-18923
Reviewers: Gordon
Ticket Links:
http://bugs.adobe.com/jira/browse/SDK-18923
Modified Paths:
flex/sdk/trunk/frameworks/projects/flex4/src/mx/graphics/graphicsClasses/TextBlockCompose r.as
flex/sdk/trunk/frameworks/projects/flex4/src/mx/graphics/graphicsClasses/TextFlowComposer .as

Answer 1

Yup, you guys pointed me in the right direction.
I changed my adjustmentListener to the following:
JScrollBar scrollBar = (JScrollBar) e.getSource();
int endLoc = document.getLength();
try {
    Rectangle end = outputArea.modelToView(endLoc);
    if (end != null) {
        int n = scrollBar.getValue() + scrollBar.getVisibleAmount();
        boolean locked = (end.y >= n && n <= (end.y + end.height));
} catch (BadLocationException ex) {
}By comparing scrollbar position with the visible rectangle of the end of the document, I can now easily tell if the user has moved the tracker back or not.
To go to the next step of automatically pausing scrolling whenever the user is moving the slider back, I also had to disable the automatic scrolling performed by DefaultCaret. Because there was no way to tell if the user was scrolling or if the output was adjusting from the adjustmentListener, I also had to flag whenever I was autoscrolling.
The end result is a JTextPane that can be appended to at all, and locked by the user by using the slider. If new data arrives, the window is not scrolled, and any text selection the user has is not cleared. Perfect!