+ fixes #0001674: Allow clearing keyboard shortcuts for actions

src/Gui/DlgKeyboard.ui

@@ -194,6 +194,13 @@
        </property>
       </widget>
      </item>
+     <item>
+      <widget class="QPushButton" name="buttonClear">
+       <property name="text">
+        <string>Clear</string>
+       </property>
+      </widget>
+     </item>
      <item>
       <widget class="QPushButton" name="buttonReset">
        <property name="text">

src/Gui/DlgKeyboardImp.cpp

@@ -260,6 +260,43 @@ void DlgCustomKeyboardImp::on_buttonAssign_clicked()
     }
 }
 
+/** Clears the accelerator of the selected command. */
+void DlgCustomKeyboardImp::on_buttonClear_clicked()
+{
+    QTreeWidgetItem* item = commandTreeWidget->currentItem();
+    if (!item)
+        return;
+
+    QVariant data = item->data(1, Qt::UserRole);
+    QByteArray name = data.toByteArray(); // command name
+
+    CommandManager & cCmdMgr = Application::Instance->commandManager();
+    Command* cmd = cCmdMgr.getCommandByName(name.constData());
+    if (cmd && cmd->getAction()) {
+        Action* action = cmd->getAction();
+        action->setShortcut(QString());
+        accelLineEditShortcut->clear();
+        editShortcut->clear();
+
+        // update the tool tip
+        QString toolTip = QCoreApplication::translate(cmd->className(),
+            cmd->getToolTipText(), 0, QCoreApplication::UnicodeUTF8);
+        action->setToolTip(toolTip);
+
+        // update the status tip
+        QString statusTip = QCoreApplication::translate(cmd->className(),
+            cmd->getStatusTip(), 0, QCoreApplication::UnicodeUTF8);
+        if (statusTip.isEmpty())
+            statusTip = toolTip;
+        action->setStatusTip(statusTip);
+
+        ParameterGrp::handle hGrp = WindowParameter::getDefaultParameter()->GetGroup("Shortcut");
+        hGrp->SetASCII(name.constData(), accelLineEditShortcut->text().toUtf8());
+        buttonAssign->setEnabled(false);
+        buttonReset->setEnabled(true);
+    }
+}
+
 /** Resets the accelerator of the selected command to the default. */
 void DlgCustomKeyboardImp::on_buttonReset_clicked()
 {

src/Gui/DlgKeyboardImp.h

@@ -52,6 +52,7 @@ protected Q_SLOTS:
     void on_categoryBox_activated(int index);
     void on_commandTreeWidget_currentItemChanged(QTreeWidgetItem*);
     void on_buttonAssign_clicked();
+    void on_buttonClear_clicked();
     void on_buttonReset_clicked();
     void on_buttonResetAll_clicked();
     void on_editShortcut_textChanged(const QString&);