make alt-tab skip modal windows

src/FocusControl.cc

@@ -53,7 +53,7 @@ namespace {
 
 bool doSkipWindow(const Focusable &win, const ClientPattern *pat) {
     const FluxboxWindow *fbwin = win.fbwindow();
-    if (!fbwin || fbwin->isFocusHidden())
+    if (!fbwin || fbwin->isFocusHidden() || fbwin->isModal())
         return true; // skip if no fbwindow or if focushidden
     if (pat && !pat->match(win))
         return true; // skip if it doesn't match the pattern

src/Focusable.hh

@@ -54,8 +54,10 @@ public:
 
     /// @return true if the focusable has input focus
     virtual bool isFocused() const { return m_focused; }
-    /// @return return true if it can be focused
+    /// @return true if it can be focused
     virtual bool acceptsFocus() const { return true; }
+    /// @return true if temporarily prevented from being focused
+    virtual bool isModal() const { return false; }
 
     /// @return true if icon button should appear focused
     bool getAttentionState() const { return m_attention_state; }

src/Window.cc

@@ -3306,6 +3306,10 @@ bool FluxboxWindow::acceptsFocus() const {
     return (m_client ? m_client->acceptsFocus() : false);
 }
 
+bool FluxboxWindow::isModal() const {
+    return (m_client ? m_client->isModal() : true);
+}
+
 const FbTk::PixmapWithMask &FluxboxWindow::icon() const {
     return (m_client ? m_client->icon() : m_icon);
 }

src/Window.hh

@@ -414,6 +414,7 @@ public:
     FbTk::FbWindow &parent() { return m_parent; }
 
     bool acceptsFocus() const;
+    bool isModal() const;
     const FbTk::PixmapWithMask &icon() const;
     const FbTk::BiDiString &title() const;
     const FbTk::FbString &getWMClassName() const;