On Sun, Sep 16, 2007 at 10:41:21AM +0200, Abdelrazak Younes wrote: > Martin Vermeer wrote: > >On Sun, Sep 16, 2007 at 04:27:04AM +0200, Tommaso Cucinotta wrote: > >>Hi, > >> > >>I couldn't really understand what information is > >>stored inside the BufferView.offset_ref_ variable. > >>At a first glance, it would seem that anchor_ref_ > >>stores the "paragraph offset" that is displayed from > >>the WorkArea top line, and offset_ref_ stores the > >>"pixel offset". Namely, the top WorkArea line of > >>pixels would display the offset_ref_-th line of > >>the anchor_ref_-th paragraph. > > > >Almost right. IIRC anchor_ref_ represents the top visible paragraph, > >and offset_ref_ the offset, in pixels, of the cursor position (which may > >be in a later paragraph). > > Well, I guess this has changed in the 1.5 series (probably my doing) but > the offset_ref_ is independent from the cursor position and the > anchor_ref_ is not necessarily the top visible paragraph. > > The anchor_ref_ is really the anchor paragraph of the BufferView from > which all other paragraphs are positioned.
...which is one of the visible paragraphs, not necessarily the top one > The offset_ref_ is basically the offset position of the anchor paragraph > from the top screen (and that is 0). In effect, offset_ref_ is just the > opposite of the paragraph position on screen and I am really tempted to > rename that. > > > > >"Normalization" means making the cursor paragraph the top one on-screen. See BufferView.cpp:288 "...making the cursor paragraph the anchor one." (I think). This code doesn't actually say anything about the screen position of the anchor. > Well, in the current implementation, center() will center the cursor > position on screen, not necessarily the paragraph. OK. > > > >>Even if I keep these two values in sync with the scrollbar, > >>it seems there are other variables that decide what pars > >>the workarea starts displaying from the top. > > > >Yes. > > > >>Moreover, what var decides how the gray text background > >>is cut at the end of the doc ? > > > >Yes, that is tricky. It's years ago that I looked at this :-( > >I suspect it is in GuiWorkArea::setScrollbarParams(): > > > > // do what cursor movement does (some grey) > > h += height() / 4; > > Look at the end of BufferView::draw() to understand how the grey area > size is calculated. Are you sure? I don't see any calculation, just decision logic. > Abdel. >
