fixe possible bug when using the clear buttons

openlp/core/ui/shortcutlistform.py

@@ -29,6 +29,7 @@ import re
 
 from PyQt4 import QtCore, QtGui
 
+from openlp.core.lib import Receiver
 from openlp.core.utils import translate
 from openlp.core.utils.actions import ActionList
 from shortcutlistdialog import Ui_ShortcutListDialog
@@ -95,43 +96,7 @@ class ShortcutListForm(QtGui.QDialog, Ui_ShortcutListDialog):
             QtCore.Qt.ShiftModifier:
             key_string = u'Shift+' + key_string
         key_sequence = QtGui.QKeySequence(key_string)
-        # The action we are attempting to change.
+        if self._validiate_shortcut(self._currentItemAction(), key_sequence):
-        changing_action = self._currentItemAction()
-        shortcut_valid = True
-        for category in self.action_list.categories:
-            for action in category.actions:
-                shortcuts = self._actionShortcuts(action)
-                if key_sequence not in shortcuts:
-                    continue
-                if action is changing_action:
-                    if self.primaryPushButton.isChecked() and \
-                        shortcuts.index(key_sequence) == 0:
-                        continue
-                    if self.alternatePushButton.isChecked() and \
-                        shortcuts.index(key_sequence) == 1:
-                        continue
-                # Have the same parent, thus they cannot have the same shortcut.
-                if action.parent() is changing_action.parent():
-                    shortcut_valid = False
-                # The new shortcut is already assigned, but if both shortcuts
-                # are only valid in a different widget the new shortcut is
-                # vaild, because they will not interfere.
-                if action.shortcutContext() in [QtCore.Qt.WindowShortcut,
-                    QtCore.Qt.ApplicationShortcut]:
-                    shortcut_valid = False
-                if changing_action.shortcutContext() in \
-                    [QtCore.Qt.WindowShortcut, QtCore.Qt.ApplicationShortcut]:
-                    shortcut_valid = False
-        if not shortcut_valid:
-            QtGui.QMessageBox.warning(self,
-                translate('OpenLP.ShortcutListDialog', 'Duplicate Shortcut'),
-                unicode(translate('OpenLP.ShortcutListDialog', 'The shortcut '
-                '"%s" is already assigned to another action, please '
-                'use a different shortcut.')) % key_sequence.toString(),
-                QtGui.QMessageBox.StandardButtons(QtGui.QMessageBox.Ok),
-                QtGui.QMessageBox.Ok
-            )
-        else:
             if self.primaryPushButton.isChecked():
                 self._adjustButton(self.primaryPushButton,
                     False, text=key_sequence.toString())
@@ -227,6 +192,12 @@ class ShortcutListForm(QtGui.QDialog, Ui_ShortcutListDialog):
         new_shortcuts.append(
             QtGui.QKeySequence(self.alternatePushButton.text()))
         self.changedActions[action] = new_shortcuts
+        if not self.primaryPushButton.text():
+            # When we do not have a primary shortcut, the just entered alternate
+            # shortcut will automatically become the primary shortcut. That is
+            # why we have to adjust the primary button's text. 
+            self.primaryPushButton.setText(self.alternatePushButton.text())
+            self.alternatePushButton.setText(u'')
         self.refreshShortcutList()
 
     def onItemDoubleClicked(self, item, column):
@@ -374,6 +345,16 @@ class ShortcutListForm(QtGui.QDialog, Ui_ShortcutListDialog):
         new_shortcuts = []
         if len(action.defaultShortcuts) != 0:
             new_shortcuts.append(action.defaultShortcuts[0])
+            # We have to check if the primary default shortcut is available. But
+            # we only have to check, if the action has a default primary
+            # shortcut (an "empty" shortcut is always valid and if the action
+            # does not have a default primary shortcut, then the alternative
+            # shortcut (not the default one) will become primary shortcut, thus
+            # the check will assume that an action were going to have the same
+            # shortcut twice.
+            if not self._validiate_shortcut(action, new_shortcuts[0]) and \
+                new_shortcuts[0] != shortcuts[0]:
+                return
         if len(shortcuts) == 2:
             new_shortcuts.append(shortcuts[1])
         self.changedActions[action] = new_shortcuts
@@ -394,10 +375,60 @@ class ShortcutListForm(QtGui.QDialog, Ui_ShortcutListDialog):
             new_shortcuts.append(shortcuts[0])
         if len(action.defaultShortcuts) == 2:
             new_shortcuts.append(action.defaultShortcuts[1])
+        if len(new_shortcuts) == 2:
+            if not self._validiate_shortcut(action, new_shortcuts[1]):
+                return
         self.changedActions[action] = new_shortcuts
         self.refreshShortcutList()
         self.onCurrentItemChanged(self.treeWidget.currentItem())
 
+    def _validiate_shortcut(self, changing_action, key_sequence):
+        """
+        Checks if the given ``changing_action `` can use the given
+        ``key_sequence``. Returns ``True`` if the ``key_sequence`` can be used
+        by the action, otherwise displays a dialog and returns ``False``.
+
+        ``changing_action``
+            The action which wants to use the ``key_sequence``.
+
+        ``key_sequence``
+            The key sequence which the action want so use.
+        """
+        is_valid = True
+        for category in self.action_list.categories:
+            for action in category.actions:
+                shortcuts = self._actionShortcuts(action)
+                if key_sequence not in shortcuts:
+                    continue
+                if action is changing_action:
+                    if self.primaryPushButton.isChecked() and \
+                        shortcuts.index(key_sequence) == 0:
+                        continue
+                    if self.alternatePushButton.isChecked() and \
+                        shortcuts.index(key_sequence) == 1:
+                        continue
+                # Have the same parent, thus they cannot have the same shortcut.
+                if action.parent() is changing_action.parent():
+                    is_valid = False
+                # The new shortcut is already assigned, but if both shortcuts
+                # are only valid in a different widget the new shortcut is
+                # vaild, because they will not interfere.
+                if action.shortcutContext() in [QtCore.Qt.WindowShortcut,
+                    QtCore.Qt.ApplicationShortcut]:
+                    is_valid = False
+                if changing_action.shortcutContext() in \
+                    [QtCore.Qt.WindowShortcut, QtCore.Qt.ApplicationShortcut]:
+                    is_valid = False
+        if not is_valid:
+            Receiver.send_message(u'openlp_warning_message', {
+                u'title': translate('OpenLP.ShortcutListDialog',
+                'Duplicate Shortcut'),
+                u'message': unicode(translate('OpenLP.ShortcutListDialog',
+                'The shortcut "%s" is already assigned to another action, '
+                'please use a different shortcut.')) % key_sequence.toString()
+            })
+        return is_valid
+
     def _actionShortcuts(self, action):
         """
         This returns the shortcuts for the given ``action``, which also includes