refactoring tiling window manager

Laying out the windows in the window manager frame, is a very similar
process regardless of doing it horizontally or vertically. So the
template design pattern was applied and the general functionality was
pulled up; only specific functionalities were put into the corresponding
classes.

kNCursesDemoApp: Separated the screen into three windows vertically. The
top and bottom window contain another two windows each, lay out
horizontally. The top left window is fixed to width 1 and the top right
takes the rest of the space. Bottom two windows take 50 % of the space
each.

Remarks: There are still some rendering bugs, when hiding and showing
windows. E. g. when hiding the top or middle window with `<F1>` or
`<F2>` respectively, the bottom window has some errors. Maybe some
timing issue.

DemoApp.cpp

@@ -37,19 +37,32 @@ namespace krikkel::NCurses
             = new VerticalTilingWindowManager(Root_Window, &ncursesMutex);
         topWindowManager
             = new HorizontalTilingWindowManager(new Window(), &ncursesMutex);
+        bottomWindowManager
+            = new HorizontalTilingWindowManager(new Window(), &ncursesMutex);
 
         windowManager->addWindow(topWindowManager);
         ptyWindow = new PtyWindow(&ncursesMutex, 0, 0, 0, 0);
         windowManager->addWindow(ptyWindow);
-        dummyWindowBottom = new Window(windowManager);
+        windowManager->addWindow(bottomWindowManager);
         windowManager->updateLayout();
         windowManager->refresh();
 
-        dummyWindowTopLeft = new Window(topWindowManager);
+        dummyWindowTopLeft = new Window();
+        topWindowManager->addWindow(dummyWindowTopLeft, 1);
+        dummyWindowTopLeft->addstr("t\no\np\n \nl\ne\nf\nt\n w\ni\nn\nd\no\nw");
         dummyWindowTopRight = new Window(topWindowManager);
+        dummyWindowTopRight->addstr("top right window");
 
         topWindowManager->updateLayout();
         topWindowManager->refresh();
+
+        dummyWindowBottomLeft = new Window(bottomWindowManager);
+        dummyWindowBottomLeft->addstr("bottom left window");
+        dummyWindowBottomRight = new Window(bottomWindowManager);
+        dummyWindowBottomRight->addstr("bottom right window");
+
+        bottomWindowManager->updateLayout();
+        bottomWindowManager->refresh();
     }
 
     void DemoApp::forkShell()
@@ -110,10 +123,10 @@ namespace krikkel::NCurses
                         windowManager->refresh();
                         break;
                     case KEY_F(3):
-                        if(dummyWindowBottom->isHidden())
-                            windowManager->showWindow(dummyWindowBottom);
+                        if(bottomWindowManager->isHidden())
+                            windowManager->showWindow(bottomWindowManager);
                         else
-                            windowManager->hideWindow(dummyWindowBottom);
+                            windowManager->hideWindow(bottomWindowManager);
                         windowManager->updateLayout();
                         windowManager->refresh();
                         break;

DemoApp.hpp

@@ -23,9 +23,9 @@ namespace krikkel::NCurses
 
         private:
             VerticalTilingWindowManager *windowManager;
-            HorizontalTilingWindowManager *topWindowManager;
-            Window *dummyWindowBottom, *dummyWindowTopLeft,
-                   *dummyWindowTopRight;
+            HorizontalTilingWindowManager *topWindowManager, *bottomWindowManager;
+            Window *dummyWindowTopLeft, *dummyWindowTopRight
+                 , *dummyWindowBottomLeft, *dummyWindowBottomRight;
             PtyWindow *ptyWindow;
             std::recursive_mutex ncursesMutex;
 

HorizontalTilingWindowManager.cpp

@@ -2,6 +2,7 @@
  * @author Christian Burger (christian@krikkel.de)
  */
 
+#include "Debug.hpp"
 #include <kNCurses/HorizontalTilingWindowManager.hpp>
 #include <kNCurses/Window.hpp>
 #include <ncursesw/ncurses.h>
@@ -9,45 +10,31 @@
 
 namespace krikkel::NCurses
 {
-    using std::list;
     using std::recursive_mutex;
-    using std::scoped_lock;
 
     HorizontalTilingWindowManager::HorizontalTilingWindowManager(NCursesWindow *rootWindow, std::recursive_mutex *ncursesMutex)
             : TilingWindowManager(rootWindow, ncursesMutex)
     {}
 
-    void HorizontalTilingWindowManager::updateLayout()
+    void HorizontalTilingWindowManager::resizeAndMoveWindow(Window *window, windowDimension dimension, windowPosition position)
     {
-        scoped_lock lock(*ncursesMutex);
+        __debug_log("(" + std::to_string(position + begx()) + ", " + std::to_string(0 + begy()) + ", " + std::to_string(dimension) + ", " + std::to_string(height()) + ")");
+        window->resize(height(), dimension);
+        window->mvwin(0 + begy(), position + begx());
+    }
 
-        size_t stackSize = visibleStack.size();
-        if(stackSize == 0)
-        {
-            clear();
-            return;
-        }
+    TilingWindowManager::windowDimension HorizontalTilingWindowManager::getAvailableSpace()
+    {
+        return width();
+    }
 
-        int availableWidth = width();
-        int availableHeight = height();
-        int windowWidth =  availableWidth / stackSize - 1;
+    void HorizontalTilingWindowManager::windowBorder()
+    {
+        vline(height());
+    }
 
-        if((windowWidth + 1) * stackSize < availableWidth)
-            ++windowWidth;
-
-        uint16_t x = 0;
-        list<Window *>::iterator it = visibleStack.begin();
-        for(size_t index = 0
-                 ; index < visibleStack.size() - 1
-                 ; ++index)
-        {
-            resizeWindow(*it++, availableHeight, windowWidth, 0, x);
-            x += windowWidth;
-            {
-                move(0, x++);
-                vline(availableHeight);
-            }
-        }
-        resizeWindow(*it, availableHeight, availableWidth - x, 0, x);
+    void HorizontalTilingWindowManager::moveCursor(TilingWindowManager::windowPosition position)
+    {
+        move(0, position);
     }
 }

TilingWindowManager.cpp

@@ -4,12 +4,15 @@
 
 #include <kNCurses/TilingWindowManager.hpp>
 #include <kNCurses/Window.hpp>
+#include "Debug.hpp"
+
 #include <ncursesw/ncurses.h>
 #include <algorithm>
 
 namespace krikkel::NCurses
 {
     using std::list;
+    using std::pair;
     using std::recursive_mutex;
     using std::scoped_lock;
 
@@ -17,15 +20,23 @@ namespace krikkel::NCurses
             : Window(*rootWindow), ncursesMutex(ncursesMutex)
     {}
 
-    void TilingWindowManager::addWindow(Window *window)
+    void TilingWindowManager::addWindow(Window *window, windowDimension size)
     {
-        stack.push_back(window);
-        visibleStack.push_back(window);
+        WindowStackElement stackElement(window, size);
+        stack.push_back(stackElement);
+        visibleStack.push_back(stackElement);
     }
 
     void TilingWindowManager::hideWindow(Window *window)
     {
-        visibleStack.remove(window);
+        if(window->hidden)
+            return;
+
+        visibleStack.remove_if(
+                [window](WindowStackElement element)
+                {
+                    return element.first == window;
+                });
         window->hidden = true;
     }
 
@@ -34,18 +45,18 @@ namespace krikkel::NCurses
         if(!window->hidden)
             return;
 
-        list<Window *>::iterator currentVisibleWindow = visibleStack.begin();
-        for(Window *currentWindow : stack)
+        list<WindowStackElement>::iterator currentVisibleWindowElement = visibleStack.begin();
+        for(WindowStackElement currentWindowElement : stack)
         {
-            if(currentWindow == window)
+            if(currentWindowElement.first == window)
             {
-                visibleStack.insert(currentVisibleWindow, window);
+                visibleStack.insert(currentVisibleWindowElement, currentWindowElement);
                 window->hidden = false;
                 break;
             }
-            if(currentWindow != (*currentVisibleWindow))
+            if(currentWindowElement != (*currentVisibleWindowElement))
                 continue;
-            ++currentVisibleWindow;
+            ++currentVisibleWindowElement;
         }
     }
 
@@ -62,21 +73,73 @@ namespace krikkel::NCurses
 
         int result = Window::refresh();
 
-        for(Window *window : visibleStack)
+        for(WindowStackElement stackElement : visibleStack)
             // @todo there are return values; compound them?
-            window->refresh();
+            stackElement.first->refresh();
 
         return result;
     }
 
-    SingleUserInput TilingWindowManager::readSingleUserInput()
+    void TilingWindowManager::updateLayout()
     {
-        return Window::readSingleUserInput();
+        scoped_lock lock(*ncursesMutex);
+
+        size_t stackSize = visibleStack.size();
+        if(stackSize == 0)
+        {
+            clear();
+            return;
+        }
+
+        int unitSize = getRelativeUnitSizeForVisibleWindows(getAvailableSpace()) - 1;
+        windowPosition position = 0;
+        auto lastButNotLeast = prev(visibleStack.end());
+        for(auto stackElementIterator = visibleStack.begin()
+                ; stackElementIterator != lastButNotLeast
+                ; ++stackElementIterator)
+        {
+            WindowStackElement stackElement = *stackElementIterator;
+            Window *window = stackElement.first;
+            if(!window->isHidden())
+            {
+                int windowShift;
+                int windowSize = stackElement.second;
+                if(windowSize < 0)
+                    windowShift = unitSize * (-windowSize);
+                else
+                    windowShift = windowSize;
+
+                resizeAndMoveWindow(window, windowShift, position);
+                position += windowShift;
+                __debug_log("drawing line at " + std::to_string(position));
+                moveCursor(position++);
+                windowBorder();
+            }
+         }
+       resizeAndMoveWindow((*lastButNotLeast).first, getAvailableSpace() - position, position);
     }
 
-    void TilingWindowManager::resizeWindow(Window *window, uint16_t height, uint16_t width, uint16_t y, uint16_t x)
+
+    TilingWindowManager::windowDimension TilingWindowManager::getRelativeUnitSizeForVisibleWindows(windowDimension spaceAvailable)
     {
-        window->resize(height, width);
-        window->mvwin(y, x);
+        uint16_t numberOfRelativeUnits = 0;
+        windowDimension absoluteSum = 0;
+        list<WindowStackElement>::iterator windowIterator = stack.begin();
+
+        for(WindowStackElement stackElement : visibleStack)
+        {
+            windowDimension size = stackElement.second;
+            if(size < 0)
+                numberOfRelativeUnits -= size;
+            else
+                absoluteSum += size;
+        }
+
+        windowDimension relativeUnitSize = (spaceAvailable - absoluteSum) / numberOfRelativeUnits;
+        windowDimension remainder = (spaceAvailable - absoluteSum - relativeUnitSize * numberOfRelativeUnits);
+        if(remainder > 0 && remainder * 2 < numberOfRelativeUnits)
+            ++relativeUnitSize;
+
+        return relativeUnitSize;
     }
 }

VerticalTilingWindowManager.cpp

@@ -2,6 +2,7 @@
  * @author Christian Burger (christian@krikkel.de)
  */
 
+#include "Debug.hpp"
 #include <kNCurses/VerticalTilingWindowManager.hpp>
 #include <kNCurses/Window.hpp>
 #include <ncursesw/ncurses.h>
@@ -9,45 +10,32 @@
 
 namespace krikkel::NCurses
 {
-    using std::list;
     using std::recursive_mutex;
-    using std::scoped_lock;
 
     VerticalTilingWindowManager::VerticalTilingWindowManager(NCursesWindow *rootWindow, std::recursive_mutex *ncursesMutex)
             : TilingWindowManager(rootWindow, ncursesMutex)
     {}
 
-    void VerticalTilingWindowManager::updateLayout()
+    void VerticalTilingWindowManager::resizeAndMoveWindow(Window *window, windowDimension dimension, windowPosition position)
     {
-        scoped_lock lock(*ncursesMutex);
-
-        size_t stackSize = visibleStack.size();
-        if(stackSize == 0)
-        {
-            clear();
-            return;
-        }
-
-        int availableWidth = width();
-        int availableHeight = height();
-        int windowHeight =  availableHeight / stackSize - 1;
-
-        if((windowHeight + 1) * stackSize < availableHeight)
-            ++windowHeight;
-
-        uint16_t y = 0;
-        list<Window *>::iterator it = visibleStack.begin();
-        for(size_t index = 0
-                 ; index < visibleStack.size() - 1
-                 ; ++index)
-        {
-            resizeWindow(*it++, windowHeight, availableWidth, y, 0);
-            y += windowHeight;
-            {
-                move(y++, 0);
-                hline(availableWidth);
-            }
-        }
-        resizeWindow(*it, availableHeight - y, availableWidth, y, 0);
+        __debug_log("(" + std::to_string(0 + begx()) + ", " + std::to_string(position +  begy()) + ", " + std::to_string(width()) + ", " + std::to_string(dimension) + ")");
+        window->resize(dimension, width());
+        window->mvwin(position + begy(), 0 + begx());
     }
+
+    TilingWindowManager::windowDimension VerticalTilingWindowManager::getAvailableSpace()
+    {
+        return height();
+    }
+
+    void VerticalTilingWindowManager::windowBorder()
+    {
+        hline(width());
+    }
+
+    void VerticalTilingWindowManager::moveCursor(TilingWindowManager::windowPosition position)
+    {
+        move(position, 0);
+    }
+
 }

include/kNCurses/HorizontalTilingWindowManager.hpp

@@ -17,7 +17,13 @@ namespace krikkel::NCurses
     {
         public:
             HorizontalTilingWindowManager(NCursesWindow *rootWindow, std::recursive_mutex *ncursesMutex);
-            void updateLayout() override;
+
+            void resizeAndMoveWindow(Window *window
+                                   , windowDimension dimension
+                                   , windowPosition position) override;
+            windowDimension getAvailableSpace() override;
+            void windowBorder() override;
+            void moveCursor(windowPosition position) override;
     };
 }
 

include/kNCurses/TilingWindowManager.hpp

@@ -1,5 +1,17 @@
 /**
- * @brief Window manager
+ * @brief Window manager for tiling (template pattern, abstract parent)
+ *
+ * A window manager contains windows of a given size, lays them out and can hide
+ * or show them. There is no concrete window manager for tiling horizontally and
+ * vertically at the same time. Instead nesting the window managers is adviced,
+ * since the window manager classes are derived from windows in the end.
+ *
+ * This is an abstract class used by the concrete classes
+ * `VerticalTilingWindowManager` and `HorizontalTilingWindowManager`. Both
+ * specify the virtual and protected, declared but undefined methods used by the
+ * public interface to facilitate the function depending on the orientation
+ * (horizontally or vertically).
+ *
  * @author Christian Burger (christian@krikkel.de)
  */
 
@@ -9,6 +21,7 @@
 #include "Window.hpp"
 #include <list>
 #include <mutex>
+#include <utility>
 
 namespace krikkel::NCurses
 {
@@ -17,21 +30,31 @@ namespace krikkel::NCurses
     class TilingWindowManager : public Window
     {
         public:
+            /// @todo figure out more appropiate names …
+            typedef int16_t windowDimension;
+            typedef uint16_t windowPosition;
+            typedef std::pair<Window *, windowDimension> WindowStackElement;
+
             TilingWindowManager(NCursesWindow *rootWindow, std::recursive_mutex *ncursesMutex);
-            void addWindow(Window *window);
+            void addWindow(Window *window, windowDimension size = -1);
             int resize(int rows, int cols) override;
             int refresh() override;
-            virtual void updateLayout() = 0;
+            void updateLayout();
 
             void hideWindow(Window *window);
             void showWindow(Window *window);
-            SingleUserInput readSingleUserInput();
 
         protected:
             std::recursive_mutex *ncursesMutex;
-            std::list<Window *> stack, visibleStack;
+            std::list<WindowStackElement> stack, visibleStack;
 
-            void resizeWindow(Window *window, uint16_t height, uint16_t width, uint16_t y, uint16_t x);
+            windowDimension getRelativeUnitSizeForVisibleWindows(windowDimension spaceAvailable);
+            virtual void resizeAndMoveWindow(Window *window
+                                   , windowDimension dimension
+                                   , windowPosition position) = 0;
+            virtual void windowBorder() = 0;
+            virtual windowDimension getAvailableSpace() = 0;
+            virtual void moveCursor(windowPosition position) = 0;
     };
 }
 

include/kNCurses/VerticalTilingWindowManager.hpp

@@ -17,7 +17,13 @@ namespace krikkel::NCurses
     {
         public:
             VerticalTilingWindowManager(NCursesWindow *rootWindow, std::recursive_mutex *ncursesMutex);
-            void updateLayout() override;
+
+            void resizeAndMoveWindow(Window *window
+                                   , windowDimension dimension
+                                   , windowPosition position) override;
+            windowDimension getAvailableSpace() override;
+            void windowBorder() override;
+            void moveCursor(windowPosition position) override;
     };
 }