Add ListView.selected_item helper.
[matthijs/upstream/mobilegtd.git] / src / gui / gui.py
index 33f8973fa8ddaafaa9b6f1cac3d8161d901018b3..3d4e6fb9e605627ad789dcbe7ce00b4398c88b35 100644 (file)
@@ -62,12 +62,21 @@ def applicable_functions(obj,allowed_function_names):
     return [eval('obj.%s'%function_name) for function_name in function_names]
 
 def get_key(key_name):
-    if key_name == '':
+    if not key_name:
         key = None
     else:
         key=eval('EKey%s'%key_name)
     return key
 
+def key_shortname(key_name):
+    """ Find the one-character name for a key """
+    if not key_name:
+        return None
+    elif key_name == 'Backspace':
+        return 'C'
+    else:
+        return key_name
+
 def all_key_names():
     return filter(lambda entry:entry[0:4]=='EKey',dir(key_codes))
 def all_key_values():
@@ -102,6 +111,8 @@ def restore_gui(object):
 
 class View(object):
     def __init__(self):
+        # Store a list of keys we bound, so we can unbind them
+        self.menu_keys = []
         self.title = None
         self.view = None
         self.lock = Ao_lock()
@@ -131,146 +142,227 @@ class View(object):
                 self.refresh()
                 self.lock.wait()
         except:
-            pass
+            # TODO: Find out which exceptions to catch here. Catching
+            # and silencing all exceptions is not a good idea.
+            raise
         restore_gui(self)
 
     def exit(self):
         self.exit_flag = True
         self.lock.signal()
-        super(View, self).exit()
+
+    def update(self,subject=None):
+        """
+        Update the current view (e.g., make sure refresh is called). We
+        can't call it directly, since we're in another thread.
+        """
+        if self.lock:
+            self.lock.signal()
 
     def refresh(self):
         """
-        Update the gui after a change in model or some user interaction.
-        Should be filled by subclasses.
+        Called when the current view must be updated. Never call
+        directly. Subclasses should extend this method, not update.
         """
-        super(View, self).refresh()
+        pass
 
-    def get_menu_entries(self):
-        """ Returns a list of menu entries to display. Will be
-        automatically updated on each refresh.
+    def refresh_menu(self):
+        """
+        Refresh the menu and its bindings. Calls self.menu_items() to
+        get the new menu.
+        """
+        # Two helper functions
+        def shortcut_prefix(key_name):
+            short = key_shortname(key_name)
+            return '[%s]' % short if short else '   '
 
-        Each menu entry is a tuple of a title for the entry and a
-        function to call when the entry is selected.
+        def do_entry((text, callback, key_name)):
+            key = get_key(key_name)
+            if key:
+                self.view.bind(key, callback)
+                self.menu_keys.append(key)
+            title = "%s %s" % (shortcut_prefix(key_name), text)
+            return(title, callback)
+
+        # Clear the bindings we previously added (we can't just clear
+        # all bindings, since other classes might have added other
+        # bindings)
+        for key in self.menu_keys:
+            self.view.bind(key, no_action)
+        self.menu_keys = []
+    
+        # Set the menu, and let do_entry add binds at the same time.
+        appuifw.app.menu = [do_entry(item) for item in self.menu_items()]
+
+    def menu_items(self):
         """
-        return []
+        Should return a list of menu items. Each menu item is a tuple:
+        (text, callback, shortcut key name).
+        """
+        return [(u'Exit', self.exit, None)]
 
 class ListView(View):
     def __init__(self):
         super(ListView, self).__init__()
+        self.current_index = None
         self.set_view(appuifw.Listbox(self.items(),self.entry_selected))
+        self.view.bind(EKeyUpArrow,lambda: self.arrow_key_pressed(-1))
+        self.view.bind(EKeyDownArrow,lambda: self.arrow_key_pressed(1))
+
+    def arrow_key_pressed(self, dir):
+        """
+        This function is called when an arrow key is pressed. Since we
+        don't get any "current list index has changed" events, we'll
+        have to create these ourselves this way.
+
+        Since the current index is only updated after the key event,
+        we'll have to adjust the index with the direction of the
+        keypress (-1 for up, +1 for down).
+        """
+        self.current_index = self.wrap_index(self.selected_index() + dir)
+        self.index_changed()
+        self.current_index = None
+
+    def run(self):
+        self.index_changed()
+        super(ListView, self).run()
 
     def entry_selected(self):
         """
         This function is called when the user selects an an entry (e.g.,
         navigates to it and push the ok button).
         """
-        super(ListView).entry_selected()
-    
-    def update(self,subject=None):
-        #logger.log(u'Updated %s'%repr(self))
-        if self.lock:
-            self.lock.signal()
-        #pass
+        pass
 
-    def index_changed(self,adjustment=None):
-        if adjustment:
-            index = self.selected_index() + adjustment
-        else:
-            index = self.selected_index()
-        if index < 0:
-            index = len(self.widgets) - 1
-        if index >= len(self.widgets):
-            index = 0
-        self.set_bindings_for_selection(index)
+    def index_changed(self):
+        """
+        This function is called when the index changes. The given index
+        is the new index (don't use self.selected_index() here, since it
+        won't be correct yet!).
+        """
+        pass
 
-    def refresh(self):
-        appuifw.app.menu=self.get_menu_entries()
+    def items(self):
+        """ This function should return the list of items to display.
+        See appuifw.ListBox for valid elements for this list. """
+        return []
 
     def set_index(self,index):
-        if index > len(self.widgets):
-            index = len(self.widgets)
-        if index < 0:
-            index = 0
-        self.view.set_list(self.items(),index)
+        """ Changes the currently selected item to index. """
+        self.view.set_list(self.items(),index % len(self.items()))
+
+    def selected_item(self):
+        """ Returns the (title of the) currently selected list item. """
+        if not self.items_cache:
+            return None # No items, so none is selected.
+        return self.items_cache[self.selected_index()]
+
 
     def selected_index(self):
-        return self.view.current()
+        """ Returns the currently selected index. """
+        if not self.current_index is None:
+            # We allow the current index to be overridden, so it can be
+            # valid during index_changed events. See arrow_key_pressed.
+            return self.current_index 
+        else:
+            return self.view.current()
+
+    def clip_index(self, index):
+        """
+        Make sure the given index fits within the bounds of this
+        list. If it doesn't, clip it off at the ends of the list (e.g,
+        -1 becomes 0).
+        """
+        max_index = len(self.items_cache) - 1
+        return max (0, min(max_index, index))
 
+    def wrap_index(self, index):
+        """
+        Make sure the given index fits within the bounds of this
+        list. If it doesn't, wrap it around (e.g., -1 becomes 5 in a
+        6-element list).
+        """
+        count = len(self.items_cache)
+        return index % count
+    
 class WidgetBasedListView(ListView):
     def __init__(self):
+        self.binding_map = {}
         self.widgets = self.generate_widgets()
         super(WidgetBasedListView,self).__init__()
 
-    def run(self):
+    def index_changed(self):
+        self.refresh_menu()
+        super(WidgetBasedListView, self).index_changed()
+
+    def entry_selected(self):
+        self.current_widget().change()
         self.refresh()
-        self.set_bindings_for_selection(0)
-        ListView.run(self)
 
     def notify(self,object,attribute,new=None,old=None):
         self.refresh()
+
     def refresh(self):
         self.widgets = self.generate_widgets()
         self.redisplay_widgets()
         super(WidgetBasedListView,self).refresh()
+
     def redisplay_widgets(self):
+        """
+        Redisplay the widgets. Should be called if the widgets
+        themselves have changed, does not call generate_widgets again.
+        """
         self.set_index(self.selected_index())
+
     def items(self):
+        # Let ListView show each widget's text.
         return self.all_widget_texts()
+
     def all_widget_texts(self):
+        """
+        Return the widget texts as they should be displayed in the
+        list view.
+        """
         return [entry.list_repr() for entry in self.widgets]
 
-    
-
     def current_widget(self):
+        """ Returns the currently selected widget. """
         return self.widgets[self.selected_index()]
-        
-
-class KeyBindingView(View):
-    
-    def __init__(self):
-        self.binding_map = {}
-        super(KeyBindingView,self).__init__()
 
-    def set_keybindings(self, binding_map):
+    def generate_widgets():
+        """ This function should return a list of widgets. """
+        return []
+        
+    def menu_items(self):
+        # Determine the current menu based on the methods available on
+        # the selected widget and on ourselves.
+        menu_items = []
+        for function in applicable_functions(self.current_widget(),self.binding_map)+\
+            applicable_functions(self,self.binding_map):
+            (key,description) = self.binding_map[function.__name__]
+            def do_callback():
+                function()
+                self.update()
+            menu_items.append((description, do_callback, key))
+        menu_items += super(WidgetBasedListView, self).menu_items()
+        return menu_items
+
+    def set_menu(self, binding_map):
         """
-        Set a new map of key bindings. This map maps method names to a
+        Set a new map of menu entries with hotkeys. This map maps method names to a
         tuple of keyname and description.
 
-        The method name refers to a method on the selected item, or the
-        current view.
+        Keyname is a string containing the name of the key (the
+        part after EKey, e.g., "0", "Star", etc.). Keyname can be "", in
+        which case the item has no shortcut.
 
-        Example: { 'search_item' : ('0', 'Search item') }
+        The method name refers to a method on the selected widget, or
+        the current view.
 
+        Example: { 'search_item' : ('0', 'Search item') }
         """
         self.binding_map = binding_map
 
-    def get_menu_entries(self):
-        menu_entries=[]
-        for key,key_name,description,function in self.key_and_menu_bindings(self.selected_index()):
-            if description != '':
-                if key:
-                    if key_name == 'Backspace': key_name='C'
-                    description='[%s] '%key_name +description
-                else:
-                    description='    '+description
-                menu_entries.append((description,function)) 
-        menu_entries.append((u'Exit', self.exit))
-        return menu_entries + super(KeyBindingView, self).get_menu_entries()
-
-    def set_bindings_for_selection(self,selected_index):
-        self.remove_all_key_bindings()
-        
-        for key,key_name,description,function in self.key_and_menu_bindings(selected_index):
-            if key:
-                self.view.bind(key,function)
-        self.view.bind(EKeyUpArrow,lambda: self.index_changed(-1))
-        self.view.bind(EKeyDownArrow,lambda: self.index_changed(1))
-        
-    def remove_all_key_bindings(self):
-        for key in all_key_values():
-            self.view.bind(key,no_action)
-
 class SearchableListView(WidgetBasedListView):
     def __init__(self):
         self.current_entry_filter_index = -1
@@ -305,29 +397,6 @@ class SearchableListView(WidgetBasedListView):
         self.filtered_list = self.entry_filters[self.current_entry_filter_index % len(self.entry_filters)]
         self.refresh()
 
-
-class EditableListView(SearchableListView,KeyBindingView):
-    def __init__(self):
-        super(EditableListView, self).__init__()
-
-    def key_and_menu_bindings(self,selected_index):
-        key_and_menu_bindings=[]
-        for function in applicable_functions(self.widgets[selected_index],self.binding_map)+\
-            applicable_functions(self,self.binding_map):
-            execute_and_update_function = self.execute_and_update(function)
-            (key,description) = self.binding_map[function.__name__]
-            key_and_menu_bindings.append((get_key(key),key,description,execute_and_update_function))
-        return key_and_menu_bindings
-
-    def entry_selected(self):
-        self.current_widget().change()
-        self.refresh()
-    def execute_and_update(self,function):
-        return lambda: (function(),self.refresh(),self.index_changed())
-
-    def notify(self,item,attribute,new=None,old=None):
-        self.refresh()
-
 #class DisplayableFunction:
 #    def __init__(self,display_name,function):
 #        self.display_name = display_name
@@ -338,4 +407,4 @@ class EditableListView(SearchableListView,KeyBindingView):
 #        function()
 
 # Public API
-__all__= ('EditableListView','show_config')
+__all__= ('SearchableListView','show_config')