Add ability to switch windows spatially with alt+meta+<direction>.

Patch based off code by Dominik Kapusta and Lindsay Roberts.
FEATURE: 74214

svn path=/trunk/KDE/kdebase/workspace/; revision=1030903

kwinbindings.cpp

@@ -119,6 +119,14 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
         0, slotWindowQuickTileLeft() );
     DEF2( "Window Quick Tile Right", I18N_NOOP("Quick Tile Window to the Right"),
         0, slotWindowQuickTileRight() );
+    DEF2( "Switch Window Up", I18N_NOOP("Switch to Window Above"),
+          Qt::META+Qt::ALT+Qt::Key_Up, slotSwitchWindowUp() );
+    DEF2( "Switch Window Down", I18N_NOOP("Switch to Window Below"),
+          Qt::META+Qt::ALT+Qt::Key_Down, slotSwitchWindowDown() );
+    DEF2( "Switch Window Right", I18N_NOOP("Switch to Window to the Right"),
+          Qt::META+Qt::ALT+Qt::Key_Right, slotSwitchWindowRight() );
+    DEF2( "Switch Window Left", I18N_NOOP("Switch to Window to the Left"),
+          Qt::META+Qt::ALT+Qt::Key_Left, slotSwitchWindowLeft() );
 
     a = actionCollection->addAction( "Group:Window Desktop" );
     a->setText( i18n("Window & Desktop") );

useractions.cpp

@@ -1190,6 +1190,104 @@ void Workspace::slotSendToDesktop( QAction *action )
 
     }
 
+/*!
+  Switches to the nearest window in given direction
+ */
+void Workspace::switchWindow( Direction direction )
+    {
+    if( !active_client )
+        return;
+    Client *c = active_client;
+    Client *switchTo = 0;
+    int bestScore = 0;
+    int d = c->desktop();
+    // Centre of the active window
+    QPoint curPos( c->pos().x() + c->geometry().width() / 2,
+                   c->pos().y() + c->geometry().height() / 2 );
+
+    QList<Client *> clist = stackingOrder();
+    for( QList<Client *>::Iterator i = clist.begin(); i != clist.end(); ++i )
+        {
+        if( (*i)->wantsTabFocus() && *i != c &&
+            (*i)->desktop() == d && ! (*i)->isMinimized() )
+            {
+            // Centre of the other window
+            QPoint other( (*i)->pos().x() + (*i)->geometry().width() / 2,
+                          (*i)->pos().y() + (*i)->geometry().height() / 2 );
+
+            int distance;
+            int offset;
+            switch( direction )
+                {
+                case DirectionNorth:
+                    distance = curPos.y() - other.y();
+                    offset = qAbs(other.x() - curPos.x());
+                    break;
+                case DirectionEast:
+                    distance = other.x() - curPos.x();
+                    offset = qAbs(other.y() - curPos.y());
+                    break;
+                case DirectionSouth:
+                    distance = other.y() - curPos.y();
+                    offset = qAbs(other.x() - curPos.x());
+                    break;
+                case DirectionWest:
+                    distance = curPos.x() - other.x();
+                    offset = qAbs(other.y() - curPos.y());
+                    break;
+                default:
+                    distance = -1;
+                    offset = -1;
+                }
+
+            if( distance > 0 )
+                {
+                // Inverse score
+                int score = distance + offset + ( (offset * offset) / distance );
+                if( score < bestScore || !switchTo )
+                    {
+                    switchTo = *i;
+                    bestScore = score;
+                    }
+                }
+            }
+        }
+    if( switchTo )
+        activateClient( switchTo );
+    }
+
+/*!
+  Switches to upper window
+ */
+void Workspace::slotSwitchWindowUp()
+    {
+    switchWindow( DirectionNorth );
+    }
+
+/*!
+  Switches to lower window
+ */
+void Workspace::slotSwitchWindowDown()
+    {
+    switchWindow( DirectionSouth );
+    }
+
+/*!
+  Switches to window on the right
+ */
+void Workspace::slotSwitchWindowRight()
+    {
+    switchWindow( DirectionEast );
+    }
+
+/*!
+  Switches to window on the left
+ */
+void Workspace::slotSwitchWindowLeft()
+    {
+    switchWindow( DirectionWest );
+    }
+
 /*!
   Shows the window operations popup menu for the activeClient()
  */

workspace.h

@@ -590,6 +590,11 @@ class Workspace : public QObject, public KDecorationDefines
         void slotWalkThroughWindowsAlternativeKeyChanged( const QKeySequence& seq );
         void slotWalkBackThroughWindowsAlternativeKeyChanged( const QKeySequence& seq );
 
+        void slotSwitchWindowUp();
+        void slotSwitchWindowDown();
+        void slotSwitchWindowRight();
+        void slotSwitchWindowLeft();
+
         void slotWindowOperations();
         void slotWindowClose();
         void slotWindowMove();
@@ -671,6 +676,14 @@ class Workspace : public QObject, public KDecorationDefines
         void setupWindowShortcut( Client* c );
         void checkCursorPos();
 
+        enum Direction
+            {
+            DirectionNorth,
+            DirectionEast,
+            DirectionSouth,
+            DirectionWest
+            };
+        void switchWindow( Direction direction );
         bool startKDEWalkThroughWindows( TabBoxMode mode ); // TabBoxWindowsMode | TabBoxWindowsAlternativeMode
         bool startWalkThroughDesktops( TabBoxMode mode ); // TabBoxDesktopMode | TabBoxDesktopListMode
         bool startWalkThroughDesktops();