wxruby users - Feb 2010 - Mouse wheel events in a grid cell editor?

I''m trying to do some advanced editing using Grids. I''ve
created my own
editors and updating view and model both works fine so far. Thanks to
whoever made this possible. I like wxRuby more each day!

Now I''d like to catch mousewheel events in order to increment/decrement
a grid cell editor.

I''ve tried installing a handler in begin_edit of my editor and removing
it again in end_edit.

I''ve attempted to

(a) install an event handler on the grid and forward it to an
editor-specific method

(b) install an event handler on the editor control

Neither approach worked. Any suggestions?

Thanks in advance,
Tony

---


class MyEditor < Wx::GridCellChoiceEditor
  def initialize
    super
  end

  def begin_edit row, col, grid
    get_control().evt_mousewheel {|e| on_wheel e }
    grid.evt_mousewheel {|e| on_wheel e }
  end

  def on_wheel event
    p event
  end

  def end_edit row, col, grid
    # TODO: unsubscribe evt handler
    super
  end
end
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On 24/02/2010 19:39, Tony Meier wrote:
> I''m trying to do some advanced editing using Grids. I''ve
created my own
> editors and updating view and model both works fine so far. Thanks to
> whoever made this possible. I like wxRuby more each day!
>    
Thanks - Wx::Grid is a really nice class - complex, but powerful.
> Now I''d like to catch mousewheel events in order to
increment/decrement
> a grid cell editor.
>
> I''ve tried installing a handler in begin_edit of my editor and
removing
> it again in end_edit.
>
> I''ve attempted to
>
> (a) install an event handler on the grid and forward it to an
> editor-specific method
>
> (b) install an event handler on the editor control
>    
I would have expected (a) to work - mouse events are fired on whichever 
is the topmost control where the mouse is. For an editor control, the 
mouse pointer may not be on top of the control itself.

Does the evt_mousewheel fire correctly if you have it as a constant 
event handler for the Grid?

You could try using the method Window#capture_mouse to force mouse input 
to be directed to a particular window - either the grid or the editor 
control - to see if this helps.

Failing that, please post a complete, runnable but minimal example with 
the problem and I''ll see if I can help

alex

thanks for the reply. The problem appears to be that, once the editor is 
instantiated, the grid will receive the wheel events everywhere *except* 
where the editor is visible.
> I would have expected (a) to work - mouse events are fired on whichever
> is the topmost control where the mouse is. For an editor control, the
> mouse pointer may not be on top of the control itself.
it would appear that is the case - which may be why the grid receives 
the wheel events but not the editor.
> Does the evt_mousewheel fire correctly if you have it as a constant
> event handler for the Grid?
yes
> You could try using the method Window#capture_mouse to force mouse input
> to be directed to a particular window - either the grid or the editor
> control - to see if this helps.
I will have to try that - digging into it now.
> Failing that, please post a complete, runnable but minimal example with
> the problem and I''ll see if I can help
attached. I will let you know as soon as I found out anything regarding 
the capture_mouse method.

tony

---

(I''m getting an "application error" from the webserver when I
try to
attach a file so I''m adding it here and reporting the bug to the 
webmaster)

#!/usr/bin/env arch -i386 ruby
begin
  require ''rubygems''
rescue LoadError
end
require ''wx''

class MyGridTable < Wx::GridTableBase
  attr_reader :cols, :rows
  def initialize(rows, cols)
    super()
    @rows = rows
    @cols = cols
  end

  def get_number_rows
    @rows
  end

  def get_number_cols
    @cols
  end

  def get_value(row, col)
    (col + @cols * row).to_s
  end

  def get_attr(row, col, attr_kind)
    Wx::GridCellAttr.new
  end

  def is_empty_cell(row, col)
    false
  end

  def set_value(x, y, val)
    puts "Attempting to change cell (#{x}, #{y}) to
''#{val}''"
  end

  def get_type_name(row, col)
    "FOOBAR"
  end
end

class MyEditor < Wx::GridCellChoiceEditor
  def initialize
   
super([''7'',''13'',''23'',''42''])
  end

  def begin_edit row, col, grid
    puts "begin edit"
    grid.evt_mousewheel {|e| on_wheel e }
    super
  end

  def on_wheel event
    p event
  end

  def end_edit(row, col, grid)
    puts "end edit"
    # TODO: how to unsubscribe?
    super
  end
end

class GridFrame < Wx::Frame
  def initialize()
    super(nil, :title => ''Mousewheel example'', :size =>
[600, 300])
    main_sizer = Wx::VBoxSizer.new

    @grid = Wx::Grid.new(self)

    @grid.register_data_type( "FOOBAR",
                              Wx::GridCellStringRenderer.new,
                              MyEditor.new )

    @grid.table = MyGridTable.new(10, 10)
    main_sizer.add(@grid, 1, Wx::EXPAND|Wx::ALL, 5)
    self.sizer = main_sizer
  end
end

Wx::App.run do
  GridFrame.new.show
end
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> You could try using the method Window#capture_mouse to force mouse input
> to be directed to a particular window - either the grid or the editor
> control - to see if this helps.
I''m a bit puzzled my how the capture_mouse method might work on the
grid
cells.

Since the cell editors don''t subclass Wx::Window, the only chance would
be to capture the mouse on the control itself and subsequently connect 
the control to the mouse event:

class MyEditor < Wx::GridCellNumberEditor

  def initialize
    super 0, 100
  end

  def begin_edit row, col, grid
    control = get_control()
    control.capture_mouse()
    connect(control.wx_id, Wx::ID_ANY, Wx::EVT_MOUSEWHEEL) { |e| p e }
    super
  end

  def end_edit row, col, grid
    control = get_control
    control.release_mouse
    super
  end

end

... however this doesn''t do anything for me (no output). Please help.

Thanks,
Tony
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