ruby-****@sourc*****
ruby-****@sourc*****
2012年 9月 19日 (水) 12:07:32 JST
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REMOTE_ADDR = 184.145.80.187
REMOTE_HOST =
URL = http://ruby-gnome2.sourceforge.jp/hiki.cgi?tut-gtk2-treev-parts
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@@ -92,7 +92,7 @@
# -- ig: append the next extension here
Cell renderers are composed of properties that define how each cell of data is rendered to the screen. There are a number of ways to set cell renderer properties, and it isn't expected that a Gtk::CellRenderer objects keep any permanent state around. This, however, is a more complex issue and hardly appropriate for an introductory text to Gtk::CellRenderer. Nevertheless, you have to be aware of one important feature here. Namely, all the properties you can set for a Gtk::CellRenderer apply to entire column. And even this can be vastly incorrect, namely, if that was strictly true, we could not set different rows to different colours and styles. This is why the above paragraph where you find the following statement: ((*"... cell renderer does not render just one single cell, but is responsible for rendering part or whole of a tree view column for each single row. It basically starts in the first row and renders its part of the column there. Then it proceeds to the next row and
renders its part of the column there again. And so on"*))is so important.
-Namely, considering what was just repeated in the highlighted text, we can subsume that while any column is processed from first row to the last, during this process, each cell is capable of triggering certain actions in which according to some model-data for that particular row renderer's property can be modified. This mechanism is called((*Cell Data Functions*))and its syntax is covered in API for Gtk::TreeViewColumn#set_cell_data_func, and about which we will talk latter in this tutorial. For now you should just know, that while a renderer is processing (ie. rendering) cells each cell is capable of modifying renderer's properties according to some criteria that is stored in the model along with our data to be displayed.
+Namely, considering what was just repeated in the highlighted text, we can subsume that while any column is processed from first row to the last, during this process, each cell is capable of triggering certain actions in which according to some model-data for that particular row renderer's property can be modified. This mechanism is called((*Cell Data Functions*))and its syntax is covered in API for Gtk::TreeViewColumn#set_cell_data_func, and about which we will talk latter in this tutorial. For now you should just know, that while a renderer is processing (ie. rendering) cells each cell is capable of modifying renderer's properties according to some criteria that is stored in the model along with our data to be displayed. (Whatever sets certain renderer's property last, that property remains set until at some later point in another row the same property is changed again by the call to "cell data function".)
:Note:
If you are just starting to learn Gtk+, the sophistication in the last paragraph can be completely ignored without the fear of adversely affecting your understanding of the tutorial. You will have a chance to gradually understand what is at stake here, when you will see how this works in example programs I provide later on in this article as well as on the following pages in this chapter (starting with the "Grocery List" program called liststore.rb).