366443 - Component::GetExtents() returns screen coordinates when ATK_XY_WINDOW passed in

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[parente]

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9a1) Gecko/20061218 Minefield/3.0a1

Background
According to the AT-SPI IDL doc, the coordType parameter to getOffsetAtPoint behaves as follows:

"if 1, they [the x,y values] are relative to the toplevel window containing this Text object."

1) Open the attached test page.
2) Resize it so the paragraph soft wraps across a few visual lines.
3) Use Component::getExtents(1) to get the window-relative x,y,w,h for the paragraph.
4) Use Text::getTextAtOffset(x, y, 1) to get the offset of the character in the upper left corner of the paragraph.

Result: -1 is returned. 

5) Use Text::getTextAtOffset(x+3, y+3, 1) to move in a few pixels to make sure the character isn't being missed because it's on the border.

Result: -1 is returned.

6) Use Text::getTextAtOffset(0, 0, 1) in case the method expects coords relative to the Text box boundary (contrary to the AT-SPI IDL statement).

Result: -1 is returned.

Guessing some random x,y values I can get it to return some offset into the text, but the basis for the numbers that actually work is unknown. 

This is a problem for screen readers that need to determine whether part of an item is obscured on the screen by the edge of the HTML pane.

Comment 1

[parente]

Attachment: Test page, resize so text wraps

Comment 2

[Scott Haeger]

Firefox returns screen coordinates for Component::getExtents(1) when window coordinates are requested.  Component::getExtents(0) returns the correct values when screen coordinates are requested

Comment 3

[Aaron Leventhal]

Peter, could the problem actually be with Component::getExtents(1)? It sounds like that's what Scott Haeger is saying.

Comment 4

[Aaron Leventhal]

Attachment: Needs testing

Comment 5

[parente]

Aaron, yes. The problem is with Component::getExtents(1).

Comment 6

[Aaron Leventhal]

Attachment: Subtract top left of window if asking for ATK_XY_WINDOW. Return bounds of 0 for error case.