Linux/X11: Prefer CLIPBOARD selection to PRIMARY

As specified in https://specifications.freedesktop.org/clipboards-spec/clipboards-latest.txt, CLIPBOARD should be used for explicit cut/copy/paste operations over PRIMARY

modules/juce_gui_basics/native/x11/juce_linux_X11_DragAndDrop.cpp

@@ -60,17 +60,19 @@ public:
         s.xselection.property  = None;
         s.xselection.time      = evt.xselectionrequest.time;
 
+        auto* display = getDisplay();
+
         if (allowedTypes.contains (targetType))
         {
             s.xselection.property = evt.xselectionrequest.property;
 
-            X11Symbols::getInstance()->xChangeProperty (getDisplay(), evt.xselectionrequest.requestor, evt.xselectionrequest.property,
+            X11Symbols::getInstance()->xChangeProperty (display, evt.xselectionrequest.requestor, evt.xselectionrequest.property,
                                                         targetType, 8, PropModeReplace,
                                                         reinterpret_cast<const unsigned char*> (textOrFiles.toRawUTF8()),
                                                         (int) textOrFiles.getNumBytesAsUTF8());
         }
 
-        X11Symbols::getInstance()->xSendEvent (getDisplay(), evt.xselectionrequest.requestor, True, 0, &s);
+        X11Symbols::getInstance()->xSendEvent (display, evt.xselectionrequest.requestor, True, 0, &s);
     }
 
     void handleExternalDragAndDropStatus (const XClientMessageEvent& clientMsg)
@@ -81,9 +83,11 @@ public:
             canDrop         = false;
             silentRect      = {};
 
+            const auto& atoms = getAtoms();
+
             if ((clientMsg.data.l[1] & 1) != 0
-                && ((Atom) clientMsg.data.l[4] == getAtoms().XdndActionCopy
-                    || (Atom) clientMsg.data.l[4] == getAtoms().XdndActionPrivate))
+                && ((Atom) clientMsg.data.l[4] == atoms.XdndActionCopy
+                    || (Atom) clientMsg.data.l[4] == atoms.XdndActionPrivate))
             {
                 if ((clientMsg.data.l[1] & 2) == 0) // target requests silent rectangle
                     silentRect.setBounds ((int) clientMsg.data.l[2] >> 16, (int) clientMsg.data.l[2] & 0xffff,
@@ -112,8 +116,11 @@ public:
 
     void handleExternalDragMotionNotify()
     {
-        auto newTargetWindow = externalFindDragTargetWindow (X11Symbols::getInstance()->xRootWindow (getDisplay(),
-                                                                                                     X11Symbols::getInstance()->xDefaultScreen (getDisplay())));
+        auto* display = getDisplay();
+
+        auto newTargetWindow = externalFindDragTargetWindow (X11Symbols::getInstance()
+                                                               ->xRootWindow (display,
+                                                                              X11Symbols::getInstance()->xDefaultScreen (display)));
 
         if (targetWindow != newTargetWindow)
         {
@@ -153,13 +160,15 @@ public:
                                                                                            (int) clientMsg.data.l[2] & 0xffff));
         dropPos -= peer->getBounds().getPosition();
 
-        auto targetAction = getAtoms().XdndActionCopy;
+        const auto& atoms = getAtoms();
 
-        for (int i = numElementsInArray (getAtoms().allowedActions); --i >= 0;)
+        auto targetAction = atoms.XdndActionCopy;
+
+        for (int i = numElementsInArray (atoms.allowedActions); --i >= 0;)
         {
-            if ((Atom) clientMsg.data.l[4] == getAtoms().allowedActions[i])
+            if ((Atom) clientMsg.data.l[4] == atoms.allowedActions[i])
             {
-                targetAction = getAtoms().allowedActions[i];
+                targetAction = atoms.allowedActions[i];
                 break;
             }
         }
@@ -206,12 +215,14 @@ public:
             return;
         }
 
+        const auto& atoms = getAtoms();
+
         dragAndDropSourceWindow = (::Window) clientMsg.data.l[0];
 
         if ((clientMsg.data.l[1] & 1) != 0)
         {
             XWindowSystemUtilities::ScopedXLock xLock;
-            XWindowSystemUtilities::GetXProperty prop (dragAndDropSourceWindow, getAtoms().XdndTypeList, 0, 0x8000000L, false, XA_ATOM);
+            XWindowSystemUtilities::GetXProperty prop (dragAndDropSourceWindow, atoms.XdndTypeList, 0, 0x8000000L, false, XA_ATOM);
 
             if (prop.success && prop.actualType == XA_ATOM && prop.actualFormat == 32 && prop.numItems != 0)
             {
@@ -244,9 +255,9 @@ public:
         }
 
         for (int i = 0; i < srcMimeTypeAtomList.size() && dragAndDropCurrentMimeType == 0; ++i)
-            for (int j = 0; j < numElementsInArray (getAtoms().allowedMimeTypes); ++j)
-                if (srcMimeTypeAtomList[i] == getAtoms().allowedMimeTypes[j])
-                    dragAndDropCurrentMimeType = getAtoms().allowedMimeTypes[j];
+            for (int j = 0; j < numElementsInArray (atoms.allowedMimeTypes); ++j)
+                if (srcMimeTypeAtomList[i] == atoms.allowedMimeTypes[j])
+                    dragAndDropCurrentMimeType = atoms.allowedMimeTypes[j];
 
         handleDragAndDropPosition (clientMsg, peer);
     }
@@ -326,22 +337,26 @@ public:
         targetWindow       = windowH;
         completionCallback = std::move (cb);
 
-        allowedTypes.add (XWindowSystemUtilities::Atoms::getCreating (getDisplay(), isText ? "text/plain" : "text/uri-list"));
+        auto* display = getDisplay();
+
+        allowedTypes.add (XWindowSystemUtilities::Atoms::getCreating (display, isText ? "text/plain" : "text/uri-list"));
 
         auto pointerGrabMask = (unsigned int) (Button1MotionMask | ButtonReleaseMask);
 
         XWindowSystemUtilities::ScopedXLock xLock;
 
-        if (X11Symbols::getInstance()->xGrabPointer (getDisplay(), windowH, True, pointerGrabMask,
+        if (X11Symbols::getInstance()->xGrabPointer (display, windowH, True, pointerGrabMask,
                                                      GrabModeAsync, GrabModeAsync, None, None, CurrentTime) == GrabSuccess)
         {
+            const auto& atoms = getAtoms();
+
             // No other method of changing the pointer seems to work, this call is needed from this very context
-            X11Symbols::getInstance()->xChangeActivePointerGrab (getDisplay(), pointerGrabMask, (Cursor) createDraggingHandCursor(), CurrentTime);
+            X11Symbols::getInstance()->xChangeActivePointerGrab (display, pointerGrabMask, (Cursor) createDraggingHandCursor(), CurrentTime);
 
-            X11Symbols::getInstance()->xSetSelectionOwner (getDisplay(), getAtoms().XdndSelection, windowH, CurrentTime);
+            X11Symbols::getInstance()->xSetSelectionOwner (display, atoms.XdndSelection, windowH, CurrentTime);
 
             // save the available types to XdndTypeList
-            X11Symbols::getInstance()->xChangeProperty (getDisplay(), windowH, getAtoms().XdndTypeList, XA_ATOM, 32, PropModeReplace,
+            X11Symbols::getInstance()->xChangeProperty (display, windowH, atoms.XdndTypeList, XA_ATOM, 32, PropModeReplace,
                                                         reinterpret_cast<const unsigned char*> (allowedTypes.getRawDataPointer()), allowedTypes.size());
 
             dragging = true;
@@ -358,32 +373,36 @@ public:
 
 private:
     //==============================================================================
-    XWindowSystemUtilities::Atoms& getAtoms() const  { return XWindowSystem::getInstance()->getAtoms(); }
-    ::Display* getDisplay() const                    { return XWindowSystem::getInstance()->getDisplay(); }
+    const XWindowSystemUtilities::Atoms& getAtoms() const noexcept  { return XWindowSystem::getInstance()->getAtoms(); }
+    ::Display* getDisplay() const noexcept                          { return XWindowSystem::getInstance()->getDisplay(); }
 
     //==============================================================================
     void sendDragAndDropMessage (XClientMessageEvent& msg)
     {
+        auto* display = getDisplay();
+
         msg.type      = ClientMessage;
-        msg.display   = getDisplay();
+        msg.display   = display;
         msg.window    = dragAndDropSourceWindow;
         msg.format    = 32;
         msg.data.l[0] = (long) windowH;
 
         XWindowSystemUtilities::ScopedXLock xLock;
-        X11Symbols::getInstance()->xSendEvent (getDisplay(), dragAndDropSourceWindow, False, 0, (XEvent*) &msg);
+        X11Symbols::getInstance()->xSendEvent (display, dragAndDropSourceWindow, False, 0, (XEvent*) &msg);
     }
 
     bool sendExternalDragAndDropMessage (XClientMessageEvent& msg)
     {
+        auto* display = getDisplay();
+
         msg.type      = ClientMessage;
-        msg.display   = getDisplay();
+        msg.display   = display;
         msg.window    = targetWindow;
         msg.format    = 32;
         msg.data.l[0] = (long) windowH;
 
         XWindowSystemUtilities::ScopedXLock xLock;
-        return X11Symbols::getInstance()->xSendEvent (getDisplay(), targetWindow, False, 0, (XEvent*) &msg) != 0;
+        return X11Symbols::getInstance()->xSendEvent (display, targetWindow, False, 0, (XEvent*) &msg) != 0;
     }
 
     void sendExternalDragAndDropDrop()
@@ -416,7 +435,9 @@ private:
         XClientMessageEvent msg;
         zerostruct (msg);
 
-        msg.message_type = getAtoms().XdndPosition;
+        const auto& atoms = getAtoms();
+
+        msg.message_type = atoms.XdndPosition;
 
         auto mousePos = Desktop::getInstance().getMousePosition();
 
@@ -428,7 +449,7 @@ private:
         msg.data.l[1] = 0;
         msg.data.l[2] = (mousePos.x << 16) | mousePos.y;
         msg.data.l[3] = CurrentTime;
-        msg.data.l[4] = (long) getAtoms().XdndActionCopy; // this is all JUCE currently supports
+        msg.data.l[4] = (long) atoms.XdndActionCopy; // this is all JUCE currently supports
 
         expectingStatus = sendExternalDragAndDropMessage (msg);
     }
@@ -469,9 +490,11 @@ private:
 
         if (dragAndDropSourceWindow != None && dragAndDropCurrentMimeType != None)
         {
+            auto* display = getDisplay();
+
             XWindowSystemUtilities::ScopedXLock xLock;
-            X11Symbols::getInstance()->xConvertSelection (getDisplay(), getAtoms().XdndSelection, dragAndDropCurrentMimeType,
-                                                          XWindowSystemUtilities::Atoms::getCreating (getDisplay(), "JXSelectionWindowProperty"),
+            X11Symbols::getInstance()->xConvertSelection (display, getAtoms().XdndSelection, dragAndDropCurrentMimeType,
+                                                          XWindowSystemUtilities::Atoms::getCreating (display, "JXSelectionWindowProperty"),
                                                           requestor, (::Time) clientMsg.data.l[2]);
         }
     }

modules/juce_gui_basics/native/x11/juce_linux_XWindowSystem.cpp

@@ -1328,9 +1328,11 @@ namespace ClipboardHelpers
         int propertyFormat = 0;
         size_t numDataItems = 0;
 
-        if (evt.selection == XA_PRIMARY || evt.selection == XWindowSystem::getInstance()->getAtoms().clipboard)
+        const auto& atoms = XWindowSystem::getInstance()->getAtoms();
+
+        if (evt.selection == XA_PRIMARY || evt.selection == atoms.clipboard)
         {
-            if (evt.target == XA_STRING || evt.target == XWindowSystem::getInstance()->getAtoms().utf8String)
+            if (evt.target == XA_STRING || evt.target == atoms.utf8String)
             {
                 auto localContent = XWindowSystem::getInstance()->getLocalClipboardContent();
 
@@ -1340,15 +1342,17 @@ namespace ClipboardHelpers
                 localContent.copyToUTF8 (data, numDataItems);
                 propertyFormat = 8; // bits/item
             }
-            else if (evt.target == XWindowSystem::getInstance()->getAtoms().targets)
+            else if (evt.target == atoms.targets)
             {
                 // another application wants to know what we are able to send
                 numDataItems = 2;
                 propertyFormat = 32; // atoms are 32-bit
                 data.calloc (numDataItems * 4);
-                Atom* atoms = unalignedPointerCast<Atom*> (data.getData());
-                atoms[0] = XWindowSystem::getInstance()->getAtoms().utf8String;
-                atoms[1] = XA_STRING;
+
+                auto* dataAtoms = unalignedPointerCast<Atom*> (data.getData());
+
+                dataAtoms[0] = atoms.utf8String;
+                dataAtoms[1] = XA_STRING;
 
                 evt.target = XA_ATOM;
             }
@@ -2588,14 +2592,12 @@ void XWindowSystem::copyTextToClipboard (const String& clipText)
 {
     localClipboardContent = clipText;
 
-    X11Symbols::getInstance()->xSetSelectionOwner (display, XA_PRIMARY,       juce_messageWindowHandle, CurrentTime);
+    X11Symbols::getInstance()->xSetSelectionOwner (display, XA_PRIMARY,      juce_messageWindowHandle, CurrentTime);
     X11Symbols::getInstance()->xSetSelectionOwner (display, atoms.clipboard, juce_messageWindowHandle, CurrentTime);
 }
 
 String XWindowSystem::getTextFromClipboard() const
 {
-    String content;
-
     /* 1) try to read from the "CLIPBOARD" selection first (the "high
        level" clipboard that is supposed to be filled by ctrl-C
        etc). When a clipboard manager is running, the content of this
@@ -2605,22 +2607,29 @@ String XWindowSystem::getTextFromClipboard() const
        2) and then try to read from "PRIMARY" selection (the "legacy" selection
        filled by good old x11 apps such as xterm)
     */
-    auto selection = XA_PRIMARY;
-    Window selectionOwner = None;
 
-    if ((selectionOwner = X11Symbols::getInstance()->xGetSelectionOwner (display, selection)) == None)
+    auto getContentForSelection = [this] (Atom selectionAtom) -> String
     {
-        selection = atoms.clipboard;
-        selectionOwner = X11Symbols::getInstance()->xGetSelectionOwner (display, selection);
-    }
+        auto selectionOwner = X11Symbols::getInstance()->xGetSelectionOwner (display, selectionAtom);
+
+        if (selectionOwner == None)
+            return {};
 
-    if (selectionOwner != None)
-    {
         if (selectionOwner == juce_messageWindowHandle)
-            content = localClipboardContent;
-        else if (! ClipboardHelpers::requestSelectionContent (display, content, selection, atoms.utf8String))
-            ClipboardHelpers::requestSelectionContent (display, content, selection, XA_STRING);
-    }
+            return localClipboardContent;
+
+        String content;
+
+        if (! ClipboardHelpers::requestSelectionContent (display, content, selectionAtom, atoms.utf8String))
+            ClipboardHelpers::requestSelectionContent (display, content, selectionAtom, XA_STRING);
+
+        return content;
+    };
+
+    auto content = getContentForSelection (atoms.clipboard);
+
+    if (content.isEmpty())
+        content = getContentForSelection (XA_PRIMARY);
 
     return content;
 }

modules/juce_gui_basics/native/x11/juce_linux_XWindowSystem.h

@@ -158,13 +158,12 @@ public:
 
     void copyTextToClipboard (const String&);
     String getTextFromClipboard() const;
+    String getLocalClipboardContent() const noexcept  { return localClipboardContent; }
 
-    String getLocalClipboardContent() const    { return localClipboardContent; }
+    ::Display* getDisplay() noexcept                                { return display; }
+    const XWindowSystemUtilities::Atoms& getAtoms() const noexcept  { return atoms; }
 
-    ::Display* getDisplay()                    { return display; }
-    XWindowSystemUtilities::Atoms& getAtoms()  { return atoms; }
-
-    bool isX11Available() const noexcept       { return xIsAvailable; }
+    bool isX11Available() const noexcept  { return xIsAvailable; }
 
     //==============================================================================
     void handleWindowMessage (LinuxComponentPeer*, XEvent&) const;