从一组-- A simple program to demonstrate Gtk2Hs.
module Main (Main.main) where
import Control.Exception
import Control.Monad
import Graphics.UI.Gtk
import Graphics.UI.Gtk.OSX
showDialog :: Window -> String -> String -> IO ()
showDialog window title message = bracket
(messageDialogNew (Just window) [] MessageInfo ButtonsOk message)
widgetDestroy
(\d -> do
set d [ windowTitle := title ]
void $ dialogRun d)
main :: IO ()
main = do
void initGUI
-- Create a new window
window <- windowNew
-- Here we connect the "destroy" event to a signal handler.
-- This event occurs when we call widgetDestroy on the window
-- or if the user closes the window.
void $ on window objectDestroy mainQuit
-- Sets the border width and tile of the window. Note that border width
-- attribute is in 'Container' from which 'Window' is derived.
set window [ containerBorderWidth := 10, windowTitle := "Hello World" ]
-- Creates a new button with the label "Hello World".
button <- buttonNew
set button [ buttonLabel := "Hello World" ]
-- When the button receives the "clicked" signal, it will call the
-- function given as the second argument.
void $ on button buttonActivated (putStrLn "Hello World")
void $ on button buttonActivated $ showDialog window "THE-TITLE" "THE-MESSAGE"
-- Gtk+ allows several callbacks for the same event.
-- This one will cause the window to be destroyed by calling
-- widgetDestroy. The callbacks are called in the sequence they were added.
void $ on button buttonActivated $ do
putStrLn "A \"clicked\"-handler to say \"destroy\""
widgetDestroy window
-- Insert the hello-world button into the window.
set window [ containerChild := button ]
-- The final step is to display this newly created widget. Note that this
-- also allocates the right amount of space to the windows and the button.
widgetShowAll window
app <- applicationNew
-- blockTermination: return True to prevent quit, False to allow
on app blockTermination $ do
putStrLn "blockTermination"
return False
-- willTerminate: handle clean-up etc.
on app willTerminate $ do
putStrLn "willTerminate"
menuBar <- menuBarNew
applicationSetMenuBar app menuBar
applicationReady app
-- All Gtk+ applications must have a main loop. Control ends here
-- and waits for an event to occur (like a key press or mouse event).
-- This function returns if the program should finish.
mainGUI
个文件中，如何确定CMakeLists.txt的相应版本号？有没有比熟悉CMake功能的历史和使用反复试验更好的方法？
答案 0 :(得分：1)
CMake在其网站上有per-version documentation。使用它，您可以检查特定CMake版本是否支持您在项目中使用的所有功能。
功能包括命令名称，命令选项及其可能的值，CMake随附的模块名称。
通常项目不需要精确最小CMake版本。您可以使用合理的版本，供用户访问，并检查此版本是否支持您使用的所有功能。