Implement multi-display support

This commit implements multi-display support: the grid will be shown on
the display that currently has the cursor and can be moved through
screen borders.

Fixes #2

src/keynavish/commands.d

@@ -38,7 +38,9 @@ private void start()
     import core.sys.windows.windows : MoveWindow;
 
     resetGrid();
-    MoveWindow(windowHandle, 0, 0, grid.rect.width, grid.rect.height, false);
+
+    auto virtualScreen = virtualScreenRectangle;
+    MoveWindow(windowHandle, virtualScreen.left, virtualScreen.top, virtualScreen.width, virtualScreen.height, false);
 
     showWindow();
 }
@@ -108,24 +110,26 @@ private void cut(Direction direction, string arg)
     auto value = getCutMoveValue(direction, arg != null ? arg : "0.5");
     auto diff = (direction == Direction.up || direction == Direction.down) ? grid.rect.height - value : grid.rect.width - value;
 
+    auto virtualScreen = virtualScreenRectangle;
+
     Grid newGrid = grid;
     final switch (direction) with (Direction)
     {
         case up:
             newGrid.rect.bottom -= diff;
-            if (newGrid.rect.bottom < 0) newGrid.rect.bottom = 0;
+            if (newGrid.rect.bottom < virtualScreen.top) newGrid.rect.bottom = virtualScreen.top;
             break;
         case down:
             newGrid.rect.top += diff;
-            if (newGrid.rect.top < 0) newGrid.rect.top = 0;
+            if (newGrid.rect.top < virtualScreen.top) newGrid.rect.top = virtualScreen.top;
             break;
         case left:
             newGrid.rect.right -= diff;
-            if (newGrid.rect.right < 0) newGrid.rect.right = 0;
+            if (newGrid.rect.right < virtualScreen.left) newGrid.rect.right = virtualScreen.left;
             break;
         case right:
             newGrid.rect.left += diff;
-            if (newGrid.rect.left < 0) newGrid.rect.left = 0;
+            if (newGrid.rect.left < virtualScreen.left) newGrid.rect.left = virtualScreen.left;
             break;
     }
 
@@ -145,7 +149,9 @@ private void move(Direction direction, string arg)
 
     if (!active) return;
 
-    auto resolution = deviceResolution;
+    auto virtualScreen = virtualScreenRectangle;
+    auto virtualScreenRight = virtualScreen.left + virtualScreen.width;
+    auto virtualScreenBottom = virtualScreen.top + virtualScreen.height;
 
     auto value = getCutMoveValue(direction, arg != null ? arg : "1");
 
@@ -155,37 +161,37 @@ private void move(Direction direction, string arg)
         case up:
             newGrid.rect.top -= value;
             newGrid.rect.bottom -= value;
-            if (newGrid.rect.top < 0)
+            if (newGrid.rect.top < virtualScreen.top)
             {
-                newGrid.rect.bottom -= newGrid.rect.top;
-                newGrid.rect.top = 0;
+                newGrid.rect.bottom -= (newGrid.rect.top - virtualScreen.top);
+                newGrid.rect.top = virtualScreen.top;
             }
             break;
         case down:
             newGrid.rect.top += value;
             newGrid.rect.bottom += value;
-            if (newGrid.rect.bottom > resolution.height)
+            if (newGrid.rect.bottom > virtualScreenBottom)
             {
-                newGrid.rect.top -= (newGrid.rect.bottom - resolution.height);
-                newGrid.rect.bottom = resolution.height;
+                newGrid.rect.top -= (newGrid.rect.bottom - virtualScreenBottom);
+                newGrid.rect.bottom = virtualScreenBottom;
             }
             break;
         case left:
             newGrid.rect.left -= value;
             newGrid.rect.right -= value;
-            if (newGrid.rect.left < 0)
+            if (newGrid.rect.left < virtualScreen.left)
             {
-                newGrid.rect.right -= newGrid.rect.left;
-                newGrid.rect.left = 0;
+                newGrid.rect.right -= (newGrid.rect.left - virtualScreen.left);
+                newGrid.rect.left = virtualScreen.left;
             }
             break;
         case right:
             newGrid.rect.left += value;
             newGrid.rect.right += value;
-            if (newGrid.rect.right > resolution.width)
+            if (newGrid.rect.right > virtualScreenRight)
             {
-                newGrid.rect.left -= (newGrid.rect.right - resolution.width);
-                newGrid.rect.right = resolution.width;
+                newGrid.rect.left -= (newGrid.rect.right - virtualScreenRight);
+                newGrid.rect.right = virtualScreenRight;
             }
             break;
     }
@@ -202,7 +208,7 @@ private void warp()
 
     if (!active) return;
 
-    auto resolution = deviceResolution;
+    auto resolution = primaryDeviceResolution;
 
     auto middleX = grid.rect.left + grid.rect.width / 2;
     auto middleY = grid.rect.top + grid.rect.height / 2;

src/keynavish/grid.d

@@ -19,7 +19,7 @@ HPEN mainPen;
 HPEN borderPen;
 
 @property
-Tuple!(int, "width", int, "height") deviceResolution()
+Tuple!(int, "width", int, "height") primaryDeviceResolution()
 {
     import core.sys.windows.windows : GetDC, GetDeviceCaps, HORZRES, VERTRES;
 
@@ -32,6 +32,41 @@ Tuple!(int, "width", int, "height") deviceResolution()
     return resolution;
 }
 
+@property
+RECT[] displayRectangles()
+{
+    import core.sys.windows.windows : EnumDisplayMonitors, MONITORENUMPROC, BOOL, TRUE, HMONITOR, HDC, LPRECT, LPARAM;
+
+    RECT[] displayRectangles = [];
+
+    static extern(Windows) BOOL callback(HMONITOR, HDC, LPRECT rectangle, LPARAM userData)
+    {
+        RECT[]* displayRectangles = cast(RECT[]*) cast(void*) userData;
+
+        *displayRectangles ~= *rectangle;
+
+        return TRUE;
+    }
+
+    EnumDisplayMonitors(null, null, &callback, cast(LPARAM) cast(void*) &displayRectangles);
+
+    return displayRectangles;
+}
+
+@property
+Tuple!(int, "width", int, "height", int, "left", int, "top") virtualScreenRectangle()
+{
+    import core.sys.windows.windows : GetSystemMetrics, SM_CXVIRTUALSCREEN, SM_CYVIRTUALSCREEN, SM_XVIRTUALSCREEN, SM_YVIRTUALSCREEN;
+
+    auto virtualScreen = typeof(return)();
+    virtualScreen.width = GetSystemMetrics(SM_CXVIRTUALSCREEN);
+    virtualScreen.height = GetSystemMetrics(SM_CYVIRTUALSCREEN);
+    virtualScreen.left = GetSystemMetrics(SM_XVIRTUALSCREEN);
+    virtualScreen.top = GetSystemMetrics(SM_YVIRTUALSCREEN);
+
+    return virtualScreen;
+}
+
 const(Grid) grid()
 {
     return grid_;
@@ -55,9 +90,18 @@ void tryPopGrid()
 
 void resetGrid()
 {
-    auto resolution = deviceResolution;
+    import core.sys.windows.windows : POINT, GetCursorPos;
+    import std.algorithm : find;
+    import std.range : empty;
+
+    POINT cursorPosition;
+    auto result = GetCursorPos(&cursorPosition);
+    assert(result);
 
-    grid_.rect = RECT(0, 0, resolution.width, resolution.height);
+    auto cursorScreen = displayRectangles.find!(r => r.contains(cursorPosition));
+    assert(!cursorScreen.empty);
+
+    grid_.rect = cursorScreen[0];
     grid_.rows = 2;
     grid_.columns = 2;
     gridStack = typeof(gridStack)();
@@ -84,13 +128,15 @@ void paintGrid(HDC deviceContext)
     import std.algorithm : map;
     import std.range : repeat, join, array;
 
+    auto virtualScreen = virtualScreenRectangle;
+
     auto pointArrays = splitGrid.map!(r => [
         POINT(r.left, r.top),
         POINT(r.right, r.top),
         POINT(r.right, r.bottom),
         POINT(r.left, r.bottom),
         POINT(r.left, r.top)
-    ]).join;
+    ].map!(p => POINT(p.x - virtualScreen.left, p.y - virtualScreen.top))).join;
 
     DWORD[] sizes = uint(5).repeat(pointArrays.length).array;
 

src/keynavish/helpers.d

@@ -13,6 +13,12 @@ LONG height(RECT rect)
     return rect.bottom - rect.top;
 }
 
+bool contains(RECT rect, POINT point)
+{
+    return point.x >= rect.left && point.x < rect.right &&
+           point.y >= rect.top && point.y < rect.bottom;
+}
+
 string expandPath(string inputString)
 {
     import std.process : environment;

src/keynavish/window.d

@@ -24,7 +24,7 @@ void registerWindowClass()
 
 void createWindow()
 {
-    auto resolution = deviceResolution;
+    auto resolution = virtualScreenRectangle;
 
     windowHandle = CreateWindowEx(WS_EX_LAYERED | WS_EX_TOOLWINDOW | WS_EX_NOACTIVATE | WS_EX_TRANSPARENT | WS_EX_TOPMOST,
                                   windowClassName.ptr,