如何在自定义 CellRenderer 上检测鼠标位置

Question

一段时间以来，我一直在努力检测自定义 Gtk.CellRenderer 上的鼠标坐标。

我一直在阅读一些不错的文档，例如：

但我仍然不确定该怎么做。我已经尝试了很多事情，例如尝试使用 __gsignals__ 连接信号或尝试使用虚拟方法。

我需要这样做，因为我正在构建评级小部件。 raiting 小部件包含的开头如下：★★★★★ 我希望当用户将鼠标悬停在上面时，相对 x 位置会修改启动数。

我还想连接一个 clicked 信号以保存用户选择的启动次数。

下面是我当前的工作代码。非常感谢对此的任何帮助！

import gi
gi.require_version('Gtk', '3.0')
gi.require_version('PangoCairo', '1.0')
from gi.repository import Gtk, Gdk, cairo, Pango, PangoCairo, GObject

class CellRendererRating(Gtk.CellRenderer):
    """ Cellrenderer to display ratings from 0 to 5: ★★★★★, ★★★☆☆, etc """

    __gproperties__ = {
        'rating': ( int, # type
                    "integer prop", # nick
                    "A property that contains an integer", # blurb
                    0, # min
                    5, # max
                    0, # default
                    GObject.PARAM_READWRITE # flags
                    ),
    }

    def __init__(self):
        super().__init__()
        self.font_size=15
        self.font="Sans Bold {}".format(self.font_size)
        self.rating = 0

    def activate(event, widget, path, background_area, cell_area, flags):
        print(path)

    def do_set_property(self, pspec, value):
        setattr(self, pspec.name, value)

    def do_get_property(self, pspec):
        return getattr(self, pspec.name)

    def do_get_size(self, widget, cell_area):
        return (0, 0, self.font_size*5, self.font_size+5)

    def do_start_editing(event, widget, path, background_area, cell_area, flags):
        print('called')

    def do_render(self, cr, treeview, background_area, cell_area, flags):
        cr.translate (0, 0)
        layout = PangoCairo.create_layout(cr)
        #layout.set_font_description(FONT_CELLRATING_DESCRIPTION)

        if 'GTK_CELL_RENDERER_FOCUSED' in str(flags) and self.rating < 5:
            for i in range(5):
                if i < self.rating:
                    layout.set_text("★", -1)
                else:
                    layout.set_text("☆", -1)

                cr.save()
                PangoCairo.update_layout (cr, layout)
                cr.move_to (cell_area.x+i*(self.font_size+1), cell_area.y)
                PangoCairo.show_layout (cr, layout)
                cr.restore()

        else:
            for i in range(self.rating):
                layout.set_text("★", -1)
                cr.save()
                PangoCairo.update_layout (cr, layout)
                cr.move_to (cell_area.x+i*(self.font_size+1), cell_area.y)
                PangoCairo.show_layout (cr, layout)
                cr.restore()

GObject.type_register(CellRendererRating)


if __name__ == '__main__':


    class Window(Gtk.Window):
        def __init__(self):
            Gtk.Window.__init__(self)
            self.connect('destroy', self.on_quit)

            liststore = Gtk.ListStore(int)

            for i in range(6):
                liststore.append([i])


            treeview = Gtk.TreeView(liststore)

            treeviewcolumn = Gtk.TreeViewColumn("Rating")
            treeviewcolumn.set_resizable(True)
            cellrenderer = CellRendererRating()
            treeviewcolumn.pack_start(cellrenderer, True)
            treeviewcolumn.add_attribute(cellrenderer, 'rating', 0)
            treeview.append_column(treeviewcolumn)

            self.add(treeview)
            self.show_all()

        def on_quit(self, widget, data=None):
            Gtk.main_quit()

    w = Window()
    Gtk.main()

Answer 1

可以通过以下方式获取光标在 CellRenderer 上的位置：

def do_render(self, cr, treeview, background_area, cell_area, flags):
    mouse_x, mouse_y = treeview.get_pointer()
    cell_render_x = mouse_x - cell_area.x
    cell_render_y = mouse_y - cell_area.y

但这可能不是您问题的最佳解决方案，因为已经有一个 Rating-CellRenderer 完全符合您的要求，即 RB.CellRendererRating。我建议使用它们的实现，既可以按原样使用，也可以作为自定义版本的基础。

RB.CellRendererRating.new()

Create a cell renderer that will display some pixbufs for representing the rating of a song. It is also able to update the rating.

Source of RB.CellRendererRating

如何在自定义 CellRenderer 上检测鼠标位置

How to detect mouse position on custom CellRenderer

python-3.x

gtk3