Re: transparent canvas working in gtkextra-2?

You cannot overlap two widgets, forget about that. You need two windows 
or a paned window if you want to see both at the same time. 
Alternatively though you can embed the plot in a sheet, like in 
testgtksheet.

Al Hooton wrote:

>	I looked at the notebook, but in a quick review I could not find a way
>to see multiple pages at the same time.  
>
>	If I have the sw/sheet on one page, and the canvas/plot on another
>page, how would I handle the state where I want the user to see both of
>them at the same time overlapped?  Unless I'm missing something, this
>would require the notebook page to be able to go transparent, as well as
>the item(s) packed in to it?
>
>Thanks,
>Al
>
>
>On Mon, 2004-02-09 at 14:24, Adrian E. Feiguin wrote:
>  
>
>>I would definitely use a notebook, and switch tabs when needed. You can 
>>set the tab insensitive or inactive (I guess, I've never done it) when 
>>you don't want the user to see the sheet/canvas. Alternatively you can 
>>use container_add/remove from the SW, and gtk_widget_ref, so it doen't 
>>get destroyed when you unparent the sheet/canvas from the SW.
>>Saludos,
>><ADRIAN>
>>
>>Al Hooton wrote:
>>
>>    
>>
>>>	Hi, Adrian:
>>>
>>>	Thanks for responding so quickly, I truly do appreciate it.  Let me
>>>describe more of what I'm trying to do.
>>>
>>>	I have a situation where I want to display just a plot when the
>>>application is in one operating mode, and optionally display a sheet
>>>"under" the plot when the application is in a second operating mode.  In
>>>the second mode, the user will enter data in the sheet, and I will
>>>update the plot "over" the sheet as new data is entered.
>>>
>>>	In the descriptions below, the phrase "sw/sheet" will mean  a GtkSheet
>>>packed in to a ScrolledWindow container.
>>>
>>>	I first tried to use the fact that GtkCanvas is a subclass of GtkFixed,
>>>adding the plot as normal and adding the sw/sheet as a child of the
>>>canvas with gtk_fixed_put().  However, this doesn't work, because there
>>>is no way for the sw/sheet to be transparent (there are other side
>>>effects as well, but the fact that the sw/sheet can not be transparent
>>>causes this approach to not be workable for me).
>>>
>>>	The next thing I tried, and one that I think would work well if the
>>>canvas could be transparent, is the following (hopefully the ascii art
>>>will come through):
>>>
>>>GtkFixed
>>> |
>>> |--ScrolledWindow
>>> |    |
>>> |    |--GtkSheet
>>> |
>>> |--PlotCanvas
>>>      |
>>>      |--Plot
>>>
>>>	
>>>	In this solution, I would make the canvas/plot opaque when I did not
>>>want the user to see the sw/sheet, and I would make the canvas/plot
>>>transparent when I did want them to see the sw/sheet.  My tests so far
>>>have indicated this would work well, if only the canvas would become
>>>transparent when instructed to do so.  But, it does not.
>>>
>>>	This is why I am wondering how to get a canvas to be transparent, and
>>>if gtk_plot_canvas_set_transparent() works correctly in gtkextra-2?
>>>
>>>	I am definitely open to suggestions for other approaches to get the
>>>desired effect.
>>>
>>>	Thanks again, Adrian -- and to anybody else with some ideas to try!
>>>
>>>Regards,
>>>Al
>>>
>>>
>>>
>>>On Mon, 2004-02-09 at 11:02, Adrian E. Feiguin wrote:
>>> 
>>>
>>>      
>>>
>>>>I still don't understand what you are trying to do, If you want to show 
>>>>other widgets, use the gtkfixed capabilities as I do with the buttons in 
>>>>testgtksheet. That's the only way to show other widgets inside a canvas. 
>>>>If what you want is to do something called MDI of Window in Window, 
>>>>that's not possible with gtk. You can use a notebook to diplay the plot 
>>>>in one tab and the sheets in other tabs. You can show buttons or icons 
>>>>in a canvas and get a sheet to appear on a different window when you 
>>>>click. Those are some ideas. But again, I still don't get it. What are 
>>>>you exactly trying to do?
>>>>Saludos,
>>>><ADRIAN>
>>>>
>>>>Al Hooton wrote:
>>>>
>>>>   
>>>>
>>>>        
>>>>
>>>>>	Follow-up on this:
>>>>>
>>>>>	I have now spent pretty much the entire weekend going trying to get a
>>>>>canvas to be transparent in gtkextra-2.  It does not matter if the
>>>>>canvas has no plots, one plot, many plots -- the canvas will never go
>>>>>transparent so I can see what is behind it.
>>>>>
>>>>>	I've stepped through gtkplotcanvas.c, and related code, trying to
>>>>>figure out what is happening, but that has lead to a dead end.  It
>>>>>appears to me the code should work, in that it is not attempting to draw
>>>>>the main rectangle of the canvas when it is marked transparent. 
>>>>>However, it is still being drawn.  If I comment out the calls to
>>>>>gtk_plot_pc_draw_rectangle in gtk_plot_canvas_paint the rectangle is not
>>>>>drawn, but the canvas still appears to have a pixbuf that covers
>>>>>whatever is underneath.  I would have expected this pixbuf to be
>>>>>unrealized if the canvas widget is transparent, but I'm probably missing
>>>>>something in how this is supposed to work.
>>>>>
>>>>>	Has anybody successfully gotten a transparent canvas?  I'd really like
>>>>>to use the gtkextra-2 package for what I'm doing, but if the canvas can
>>>>>not be transparent I may have to abandon this for something else -- not
>>>>>my preference, since I already have so much work done on top of
>>>>>gtkextra-2.
>>>>>
>>>>>	Thanks!
>>>>>
>>>>>-- Al
>>>>>
>>>>>
>>>>>On Sat, 2004-02-07 at 20:20, Al Hooton wrote:
>>>>>
>>>>>
>>>>>     
>>>>>
>>>>>          
>>>>>
>>>>>>	Version: gtkextra-2 from CVS as a couple of weeks ago.
>>>>>>
>>>>>>	I have successfully been using multiple plots on a canvas, with all the
>>>>>>plots transparent.  Today for the first time, I tried making the canvas
>>>>>>transparent also, so I could see through the plots and the canvas to
>>>>>>what is below.  However, the canvas is not transparent when I set it
>>>>>>with gtk_plot_canvas_set_transparent().
>>>>>>
>>>>>>	I have tried a small test program that just creates a canvas as a child
>>>>>>of a parent window that has a blue background.  When I set the canvas to
>>>>>>transparent, I still have the while background of the canvas, instead of
>>>>>>seeing the blue background of the parent, so I know the canvas has not
>>>>>>become transparent.
>>>>>>
>>>>>>	Is this a known problem?  Do we have a workaround?
>>>>>>
>>>>>>	Thanks!
>>>>>>
>>>>>>-Al
>>>>>>
>>>>>>  
>>>>>>
>>>>>>       
>>>>>>
>>>>>>            
>>>>>>
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>>>>>.
>>>>>
>>>>>
>>>>>
>>>>>     
>>>>>
>>>>>          
>>>>>
>>>>   
>>>>
>>>>        
>>>>
>>>.
>>>
>>> 
>>>
>>>      
>>>
>>
>><!DSPAM:4028089290685711153368>
>>    
>>
>
>.
>
>  
>



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