Question

有关信息：我使用Ada作为编程语言，而Windowing软件是Gtk和GtkAda。

我在有时不适合我的窗口的绘图区域上绘制了一个绘图，即使使用全屏也是如此。因此，我需要有一个滚动区域。我使用随附的代码来获得这样的窗口，但是滚动条始终无法移动，因此看不到我的绘图的一部分。我必须在程序中添加什么？在运行的程序中必须更改滚动条的范围时，该怎么办？

    Gtk_New (MainWindow.Scrolledwindow);
    Set_Policy (MainWindow.Scrolledwindow, Policy_Always, Policy_Always);
    Set_Shadow_Type (MainWindow.Scrolledwindow, Shadow_None);
    Set_Placement (MainWindow.Scrolledwindow, Corner_Top_Left);
    Gtk_New (MainWindow.View_Port);
    Gtk_New (MainWindow.DrawingArea);
    MainWindow.Scrolledwindow.Add(MainWindow.View_Port);
    MainWindow.View_Port.Add(MainWindow.DrawingArea);
    Pack_Start
      (MainWindow.Main_Box1,
       MainWindow.Scrolledwindow,
       Expand  => True,
       Fill    => True,
       Padding => 0);

Answer 1

我认为您可以省略视口小部件，而只需将其替换为一个框。如@ lb90所述，您可以使用public List<Entity> getList() { return Stream.of( EntityService.filtermethod("AB"), EntityService.filtermethod("BC"), EntityService.filtermethod("CD") ) .flatMap(Collection::stream) .collect(Collectors.toList()); }设置绘图区域的大小。这似乎可以解决问题：

main.adb

Set_Size_Request

demo.ads

with Gtk.Main;
with Demo.Main_Window;

procedure Main is
   use Demo.Main_Window;
   Main_Window : Demo_Main_Window;
begin
   Gtk.Main.Init;
   Gtk_New (Main_Window);
   Gtk.Main.Main;
end Main;

demo-main_window.ads

package Demo is

end Demo;

demo-main_window.adb

with Glib; use Glib;

with Gtk.Window;
with Gtk.Scrolled_Window;
with Gtk.Box;
with Gtk.Drawing_Area;

package Demo.Main_Window is

   type Demo_Main_Window_Record is new Gtk.Window.Gtk_Window_Record with private;
   type Demo_Main_Window is access all Demo_Main_Window_Record'Class;

   ------------------
   -- Constructors --
   ------------------

   procedure Gtk_New
     (Main_Window : out Demo_Main_Window);
   procedure Initialize
     (Main_Window : not null access Demo_Main_Window_Record'Class);

private

   use Gtk.Scrolled_Window;
   use Gtk.Box;
   use Gtk.Drawing_Area;

   Window_Width  : constant Gint := 640;
   Window_Height : constant Gint := 480;

   Draw_Area_Width  : constant Gint := 1000;
   Draw_Area_Height : constant Gint := 1000;

   type Demo_Main_Window_Record is
     new Gtk.Window.Gtk_Window_Record with
      record
         SW : Gtk_Scrolled_Window;
         VB : Gtk_Vbox;
         DA : Gtk_Drawing_Area;
      end record;

end Demo.Main_Window;

滚动绘图区

1 个答案: