From 6a75641ca9dcf5113598fdfaf69149e29761001b Mon Sep 17 00:00:00 2001
From: jules <jules@rawmaterialsoftware.com>
Date: Fri, 21 Feb 2014 13:16:33 +0000
Subject: [PATCH] Better detection of win32 main monitor.

---
 .../native/juce_win32_Windowing.cpp           | 37 +++++++++++--------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/modules/juce_gui_basics/native/juce_win32_Windowing.cpp b/modules/juce_gui_basics/native/juce_win32_Windowing.cpp
index 6d62c85976..1d8b9daccd 100644
--- a/modules/juce_gui_basics/native/juce_win32_Windowing.cpp
+++ b/modules/juce_gui_basics/native/juce_win32_Windowing.cpp
@@ -3181,10 +3181,22 @@ void Desktop::setKioskComponent (Component* kioskModeComponent, bool enableOrDis
 }
 
 //==============================================================================
-static BOOL CALLBACK enumMonitorsProc (HMONITOR, HDC, LPRECT r, LPARAM userInfo)
+struct MonitorInfo
 {
-    Array <Rectangle<int> >* const monitorCoords = (Array <Rectangle<int> >*) userInfo;
-    monitorCoords->add (rectangleFromRECT (*r));
+    MonitorInfo (Rectangle<int> rect, bool main) noexcept  : isMain (main), bounds (rect) {}
+
+    Rectangle<int> bounds;
+    bool isMain;
+};
+
+static BOOL CALLBACK enumMonitorsProc (HMONITOR hm, HDC, LPRECT r, LPARAM userInfo)
+{
+    MONITORINFO info = { 0 };
+    info.cbSize = sizeof (info);
+    GetMonitorInfo (hm, &info);
+    const bool isMain = (info.dwFlags & 1 /* MONITORINFOF_PRIMARY */) != 0;
+    ((Array<MonitorInfo>*) userInfo)->add (MonitorInfo (rectangleFromRECT (*r), isMain));
+
     return TRUE;
 }
 
@@ -3192,16 +3204,11 @@ void Desktop::Displays::findDisplays (float masterScale)
 {
     setDPIAwareness();
 
-    Array <Rectangle<int> > monitors;
+    Array<MonitorInfo> monitors;
     EnumDisplayMonitors (0, 0, &enumMonitorsProc, (LPARAM) &monitors);
 
-    // make sure the first in the list is the main monitor
-    for (int i = 1; i < monitors.size(); ++i)
-        if (monitors.getReference(i).getPosition().isOrigin())
-            monitors.swap (i, 0);
-
     if (monitors.size() == 0)
-        monitors.add (rectangleFromRECT (getWindowRect (GetDesktopWindow())));
+        monitors.add (MonitorInfo (rectangleFromRECT (getWindowRect (GetDesktopWindow())), true));
 
     RECT workArea;
     SystemParametersInfo (SPI_GETWORKAREA, 0, &workArea, 0);
@@ -3211,12 +3218,12 @@ void Desktop::Displays::findDisplays (float masterScale)
     for (int i = 0; i < monitors.size(); ++i)
     {
         Display d;
-        d.userArea = d.totalArea = monitors.getReference(i) / masterScale;
-        d.isMain = (i == 0);
-        d.scale = masterScale;
-        d.dpi = dpi;
+        d.userArea  = d.totalArea = monitors.getReference(i).bounds / masterScale;
+        d.isMain    = monitors.getReference(i).isMain;
+        d.scale     = masterScale;
+        d.dpi       = dpi;
 
-        if (i == 0)
+        if (d.isMain)
             d.userArea = d.userArea.getIntersection (rectangleFromRECT (workArea) / masterScale);
 
         displays.add (d);