Method: WinWindow#each_child

Defined in:
lib/winwindow.rb

#each_child ⇒ Object

iterates over each child, yielding a WinWindow object.

raises a WinWindow::NotExistsError if the window does not exist, or a WinWindow::SystemError if a System Error errors.

use #children to get an Enumerable object.

msdn.microsoft.com/en-us/library/ms633494(VS.85).aspx

For System Error Codes see msdn.microsoft.com/en-us/library/ms681381(VS.85).aspx

Raises:



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# File 'lib/winwindow.rb', line 1056

def each_child
  raise WinWindow::NotExistsError, "Window does not exist! Cannot enumerate children." unless exists?
  enum_child_windows_callback= WinUser.window_enum_callback do |chwnd, lparam|
    yield WinWindow.new(chwnd)
    WIN_TRUE
  end
  begin
    ret=WinUser.EnumChildWindows(hwnd, enum_child_windows_callback, nil)
  ensure
    WinUser.remove_window_enum_callback(enum_child_windows_callback)
  end
  if ret==0
    self.class.system_error("EnumChildWindows")
    # actually, EnumChildWindows doesn't say anything about return value indicating error encountered.
    # Although EnumWindows does, so it seems sort of safe to assume that would apply here too. 
    # but, maybe not - so, should we raise an error here? 
  end
  nil
end