Body text pagesize hardcoded at 15 lines
Brian Theado
15 lines at a time instead of a page at a time. My body text page
size is never 15 and I find it to be a nuisance.
I found the leoMoveCursorHelper method of the leoQTextEditWidget class
has a linesPerPage parameter which defaults to 15.
def leoMoveCursorHelper (self,kind,extend=False,linesPerPage=15):
[...]
if kind in ('page-down','page-up'):
cursor = w.textCursor()
cursor.movePosition(op,mode,linesPerPage)
w.setTextCursor(cursor)
[...]
I thought this would be easy to fix, but after long effort, I'm
stumped. I thought this would be easy because out of the box
QTextEdit has the behavior I want. The page-up and page-down keys
moves one screenful at a time. Here's some code which shows this:
import PyQt4.QtGui as QtGui
w = QtGui.QTextEdit()
w.resize(250, 150)
w.move(300, 300)
w.setWindowTitle('QTextEdit test')
for n in range(0,300):
w.insertPlainText('%d\n' % n)
w.show()
c.brian_test_w = w
# Now manually play with page-up, page-down, resize the window, etc.
I expected the docs would tell what the default keybindings are and
what public accessible methods are called by those bindings, but they
just tell the bindings:
http://developer.qt.nokia.com/doc/qt-4.8/qtextedit.html#editing-key-bindings
Maybe my next step should have been to dive into the QT source code,
but I thought that might be a rabbit hole and decided to try internet
searches instead. I got lost in the maze of QT class documentation
with little to show for it.
I did come up with this code which moves up 1 page:
sb = w.verticalScrollBar()
sb.setSliderPosition(sb.sliderPosition() - sb.pageStep())
but that doesn't actually move the text cursor--just the visible page
text. So the cursor would end up offscreen. Also, selecting text by
page (i.e. Shift-pageup/Shift-pagedown) would be broken. The method
w.textCursor().movePosition method needs to know the number of lines,
but w.verticalScrollBar().pageStep() returns the number of pixels. I
don't know how to convert from one to the other.
The answers to any of these questions would be helpful:
1. How to query the number of lines per page from a QTextEdit?
2. How to query the linenumber of the top-most and bottom-most visible
lines in QTextEdit?
3. How to find the height of each visible line in QTextEdit?
4. What code does the default Page-Up/Page-Down code call in QTextEdit?
Does anybody know or know a good way to find out?
Brian
Edward K. Ream
> I thought this would be easy to fix, but after long effort, I'm
> stumped. I thought this would be easy because out of the box
> QTextEdit has the behavior I want.
I'm not too surprised. Qt's scrolling support classes are baroque.
One solution might be to hack Leo's key-binding code so that page
up/down keys get passed back to scrolling text widgets. But this will
not be easy, because of the complexity of Leo's key-handling code.
Edward
Brian Theado
[...]
>
> One solution might be to hack Leo's key-binding code so that page
> up/down keys get passed back to scrolling text widgets. But this will
> not be easy, because of the complexity of Leo's key-handling code.
I looked at the QT C++ source code and found the functionality which
takes care of the paging. It looked to be a private(!) method so it
can't be called, I guess. However, the method was pretty
straightforward and only called public methods. So I ported the code
to python and replaced Leo's hard-coded 15 line scrolling with it.
I checked the code in and pushed to launchpad.
Brian
HansBKK
I checked the code in and pushed to launchpad.
Edward K. Ream
> I looked at the QT C++ source code and found the functionality which
> takes care of the paging. It looked to be a private(!) method so it
> can't be called, I guess. However, the method was pretty
> straightforward and only called public methods. So I ported the code
> to python and replaced Leo's hard-coded 15 line scrolling with it.
>
> I checked the code in and pushed to launchpad.
Many thanks for this work. I'm not sure why I had so much trouble
merging your code, but just as a guess I think it was due to problems
on my side. Anyway, the code has survived the by-hand merges...
Edward
Edward K. Ream
> does this mean the # of lines per PgDn will be configurable?
As I read the code, it means that Leo will work just like typical
Qt.Text widgets do: which means that page up/down will "just work"
without any configuration needed.
Edward