From 46a97e1f2c7d9564804f8bb9f88a17d837b5b0e0 Mon Sep 17 00:00:00 2001
From: ed <eddavies95@gmail.com>
Date: Tue, 7 May 2019 17:10:52 +0100
Subject: [PATCH] Linux:  Recreate mouse cursors when showing them on a
 different display to the one that they were originally created on

---
 .../mouse/juce_MouseCursor.cpp                | 12 ++++++---
 .../native/juce_linux_X11_Windowing.cpp       | 27 ++++++++++++++++++-
 2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/modules/juce_gui_basics/mouse/juce_MouseCursor.cpp b/modules/juce_gui_basics/mouse/juce_MouseCursor.cpp
index 80e90c14f8..dd93e90eb9 100644
--- a/modules/juce_gui_basics/mouse/juce_MouseCursor.cpp
+++ b/modules/juce_gui_basics/mouse/juce_MouseCursor.cpp
@@ -53,7 +53,8 @@ public:
     }
 
     SharedCursorHandle (const Image& image, Point<int> hotSpot, float scaleFactor)
-        : handle (CustomMouseCursorInfo (image, hotSpot, scaleFactor).create()),
+        : info (new CustomMouseCursorInfo (image, hotSpot, scaleFactor)),
+          handle (info->create()),
           standardType (MouseCursor::NormalCursor),
           isStandard (false)
     {
@@ -106,10 +107,15 @@ public:
         }
     }
 
-    void* getHandle() const noexcept        { return handle; }
+    void* getHandle() const noexcept                            { return handle; }
+    void setHandle (void* newHandle)                            { handle = newHandle; }
+
+    MouseCursor::StandardCursorType getType() const noexcept    { return standardType; }
+    CustomMouseCursorInfo* getCustomInfo() const noexcept       { return info.get(); }
 
 private:
-    void* const handle;
+    std::unique_ptr<CustomMouseCursorInfo> info;
+    void* handle;
     Atomic<int> refCount { 1 };
     const MouseCursor::StandardCursorType standardType;
     const bool isStandard;
diff --git a/modules/juce_gui_basics/native/juce_linux_X11_Windowing.cpp b/modules/juce_gui_basics/native/juce_linux_X11_Windowing.cpp
index 42826ba5f7..8176b7cc30 100644
--- a/modules/juce_gui_basics/native/juce_linux_X11_Windowing.cpp
+++ b/modules/juce_gui_basics/native/juce_linux_X11_Windowing.cpp
@@ -3790,6 +3790,7 @@ int JUCE_CALLTYPE NativeMessageBox::showYesNoBox (AlertWindow::AlertIconType ico
 }
 
 //============================== X11 - MouseCursor =============================
+std::map<Cursor, Display*> cursorMap;
 
 void* CustomMouseCursorInfo::create() const
 {
@@ -3852,7 +3853,10 @@ void* CustomMouseCursorInfo::create() const
                 xcursorImageDestroy (xcImage);
 
                 if (result != nullptr)
+                {
+                    cursorMap[(Cursor) result] = display;
                     return result;
+                }
             }
         }
     }
@@ -3916,6 +3920,7 @@ void* CustomMouseCursorInfo::create() const
     XFreePixmap (display, sourcePixmap);
     XFreePixmap (display, maskPixmap);
 
+    cursorMap[(Cursor) result] = display;
     return result;
 }
 
@@ -3983,13 +3988,33 @@ void* MouseCursor::createStandardMouseCursor (MouseCursor::StandardCursorType ty
     }
 
     ScopedXLock xlock (display);
-    return (void*) XCreateFontCursor (display, shape);
+
+    auto* result = (void*) XCreateFontCursor (display, shape);
+    cursorMap[(Cursor) result] = display;
+
+    return result;
 }
 
 void MouseCursor::showInWindow (ComponentPeer* peer) const
 {
     if (auto* lp = dynamic_cast<LinuxComponentPeer*> (peer))
+    {
+        ScopedXDisplay xDisplay;
+
+        if (cursorHandle != nullptr && xDisplay.display != cursorMap[(Cursor) getHandle()])
+        {
+            auto oldHandle = (Cursor) getHandle();
+
+            if (auto* customInfo = cursorHandle->getCustomInfo())
+                cursorHandle->setHandle (customInfo->create());
+            else
+                cursorHandle->setHandle (createStandardMouseCursor (cursorHandle->getType()));
+
+            cursorMap.erase (oldHandle);
+        }
+
         lp->showMouseCursor ((Cursor) getHandle());
+    }
 }
 
 //=================================== X11 - DND ================================