Linux: Fix restoreWindowFromStateString() when the peer already exists

BREAKING-CHANGES.txt

@@ -1,6 +1,31 @@
 JUCE breaking changes
 =====================
 
+develop
+=======
+
+Change
+------
+The return type of XWindowSystem::getBorderSize() was changed to
+ComponentPeer::OptionalBorderSize.
+
+Possible Issues
+---------------
+User code that uses XWindowSystem::getBorderSize() will fail to build.
+
+Workaround
+----------
+Use operator bool() to determine the validity of the new return value and
+access the contained value using operator*().
+
+Rationale
+---------
+The XWindow system cannot immediately report the correct border size after
+window creation. The underlying X11 calls will signal whether querying the
+border size was successful, but there was no way to forward this information
+through XWindowSystem::getBorderSize() until this change.
+
+
 Version 6.1.5
 =============
 

modules/juce_audio_plugin_client/Unity/juce_Unity_Wrapper.cpp

@@ -270,6 +270,7 @@ private:
     bool isFocused() const override                                   { return true; }
     void grabFocus() override                                         {}
     void* getNativeHandle() const override                            { return nullptr; }
+    OptionalBorderSize getFrameSizeIfPresent() const override         { return {}; }
     BorderSize<int> getFrameSize() const override                     { return {}; }
     void setVisible (bool) override                                   {}
     void setTitle (const String&) override                            {}

modules/juce_gui_basics/native/juce_android_Windowing.cpp

@@ -631,6 +631,12 @@ public:
                                                                     (float) localPos.y * scale));
     }
 
+    OptionalBorderSize getFrameSizeIfPresent() const override
+    {
+        // TODO
+        return {};
+    }
+
     BorderSize<int> getFrameSize() const override
     {
         // TODO

modules/juce_gui_basics/native/juce_ios_UIViewComponentPeer.mm

@@ -211,24 +211,25 @@ public:
         controller = [newController retain];
     }
 
-    Rectangle<int> getBounds() const override               { return getBounds (! isSharedWindow); }
+    Rectangle<int> getBounds() const override                 { return getBounds (! isSharedWindow); }
     Rectangle<int> getBounds (bool global) const;
     Point<float> localToGlobal (Point<float> relativePosition) override;
     Point<float> globalToLocal (Point<float> screenPosition) override;
     using ComponentPeer::localToGlobal;
     using ComponentPeer::globalToLocal;
     void setAlpha (float newAlpha) override;
-    void setMinimised (bool) override                       {}
-    bool isMinimised() const override                       { return false; }
+    void setMinimised (bool) override                         {}
+    bool isMinimised() const override                         { return false; }
     void setFullScreen (bool shouldBeFullScreen) override;
-    bool isFullScreen() const override                      { return fullScreen; }
+    bool isFullScreen() const override                        { return fullScreen; }
     bool contains (Point<int> localPos, bool trueIfInAChildWindow) const override;
-    BorderSize<int> getFrameSize() const override           { return BorderSize<int>(); }
+    OptionalBorderSize getFrameSizeIfPresent() const override { return {}; }
+    BorderSize<int> getFrameSize() const override             { return BorderSize<int>(); }
     bool setAlwaysOnTop (bool alwaysOnTop) override;
     void toFront (bool makeActiveWindow) override;
     void toBehind (ComponentPeer* other) override;
     void setIcon (const Image& newIcon) override;
-    StringArray getAvailableRenderingEngines() override     { return StringArray ("CoreGraphics Renderer"); }
+    StringArray getAvailableRenderingEngines() override       { return StringArray ("CoreGraphics Renderer"); }
 
     void drawRect (CGRect);
     bool canBecomeKeyWindow();

modules/juce_gui_basics/native/juce_linux_Windowing.cpp

@@ -141,11 +141,17 @@ public:
         return bounds;
     }
 
-    BorderSize<int> getFrameSize() const override
+    OptionalBorderSize getFrameSizeIfPresent() const override
     {
         return windowBorder;
     }
 
+    BorderSize<int> getFrameSize() const override
+    {
+        const auto optionalBorderSize = getFrameSizeIfPresent();
+        return optionalBorderSize ? (*optionalBorderSize) : BorderSize<int>();
+    }
+
     Point<float> localToGlobal (Point<float> relativePosition) override
     {
         return relativePosition + getScreenPosition (false).toFloat();
@@ -362,9 +368,14 @@ public:
     void updateBorderSize()
     {
         if ((styleFlags & windowHasTitleBar) == 0)
-            windowBorder = {};
-        else if (windowBorder.getTopAndBottom() == 0 && windowBorder.getLeftAndRight() == 0)
+        {
+            windowBorder = ComponentPeer::OptionalBorderSize { BorderSize<int>() };
+        }
+        else if (! windowBorder
+                 || ((*windowBorder).getTopAndBottom() == 0 && (*windowBorder).getLeftAndRight() == 0))
+        {
             windowBorder = XWindowSystem::getInstance()->getBorderSize (windowH);
+        }
     }
 
     //==============================================================================
@@ -504,7 +515,7 @@ private:
 
     ::Window windowH = {}, parentWindow = {};
     Rectangle<int> bounds;
-    BorderSize<int> windowBorder;
+    ComponentPeer::OptionalBorderSize windowBorder;
     bool fullScreen = false, isAlwaysOnTop = false;
     double currentScaleFactor = 1.0;
     Array<Component*> glRepaintListeners;

modules/juce_gui_basics/native/juce_mac_NSViewComponentPeer.mm

@@ -493,12 +493,12 @@ public:
                                     : (v == view);
     }
 
-    BorderSize<int> getFrameSize() const override
+    OptionalBorderSize getFrameSizeIfPresent() const override
     {
-        BorderSize<int> b;
-
         if (! isSharedWindow)
         {
+            BorderSize<int> b;
+
             NSRect v = [view convertRect: [view frame] toView: nil];
             NSRect w = [window frame];
 
@@ -506,9 +506,19 @@ public:
             b.setBottom ((int) v.origin.y);
             b.setLeft ((int) v.origin.x);
             b.setRight ((int) (w.size.width - (v.origin.x + v.size.width)));
+
+            return OptionalBorderSize { b };
         }
 
-        return b;
+        return {};
+    }
+
+    BorderSize<int> getFrameSize() const override
+    {
+        if (const auto frameSize = getFrameSizeIfPresent())
+            return *frameSize;
+
+        return {};
     }
 
     bool hasNativeTitleBar() const

modules/juce_gui_basics/native/juce_win32_Windowing.cpp

@@ -1764,6 +1764,11 @@ public:
         return w == hwnd || (trueIfInAChildWindow && (IsChild (hwnd, w) != 0));
     }
 
+    OptionalBorderSize getFrameSizeIfPresent() const override
+    {
+        return ComponentPeer::OptionalBorderSize { windowBorder };
+    }
+
     BorderSize<int> getFrameSize() const override
     {
         return windowBorder;

modules/juce_gui_basics/native/x11/juce_linux_XWindowSystem.cpp

@@ -1802,7 +1802,7 @@ bool XWindowSystem::contains (::Window windowH, Point<int> localPos) const
           && child == None;
 }
 
-BorderSize<int> XWindowSystem::getBorderSize (::Window windowH) const
+ComponentPeer::OptionalBorderSize XWindowSystem::getBorderSize (::Window windowH) const
 {
     jassert (windowH != 0);
 
@@ -1824,7 +1824,7 @@ BorderSize<int> XWindowSystem::getBorderSize (::Window windowH) const
                 data += sizeof (unsigned long);
             }
 
-            return { (int) sizes[2], (int) sizes[0], (int) sizes[3], (int) sizes[1] };
+            return ComponentPeer::OptionalBorderSize ({ (int) sizes[2], (int) sizes[0], (int) sizes[3], (int) sizes[1] });
         }
     }
 

modules/juce_gui_basics/native/x11/juce_linux_XWindowSystem.h

@@ -181,8 +181,8 @@ public:
     void setBounds (::Window, Rectangle<int>, bool fullScreen) const;
     void updateConstraints (::Window) const;
 
-    BorderSize<int> getBorderSize   (::Window) const;
-    Rectangle<int>  getWindowBounds (::Window, ::Window parentWindow);
+    ComponentPeer::OptionalBorderSize getBorderSize (::Window) const;
+    Rectangle<int> getWindowBounds (::Window, ::Window parentWindow);
     Point<int> getPhysicalParentScreenPosition() const;
 
     bool contains (::Window, Point<int> localPos) const;

modules/juce_gui_basics/windows/juce_ComponentPeer.h

@@ -76,6 +76,31 @@ public:
 
     };
 
+    class OptionalBorderSize final
+    {
+    public:
+        OptionalBorderSize()                               : valid (false)                               {}
+        explicit OptionalBorderSize (BorderSize<int> size) : valid (true), borderSize (std::move (size)) {}
+
+        explicit operator bool() const noexcept { return valid; }
+
+        const auto& operator*() const noexcept
+        {
+            jassert (valid);
+            return borderSize;
+        }
+
+        const auto* operator->() const noexcept
+        {
+            jassert (valid);
+            return &borderSize;
+        }
+
+    private:
+        bool valid;
+        BorderSize<int> borderSize;
+    };
+
     //==============================================================================
     /** Creates a peer.
 
@@ -219,6 +244,18 @@ public:
     */
     virtual bool contains (Point<int> localPos, bool trueIfInAChildWindow) const = 0;
 
+    /** Returns the size of the window frame that's around this window.
+
+        Depending on the platform the border size may be invalid for a short transient
+        after creating a new window. Hence the returned value must be checked using
+        operator bool() and the contained value can be accessed using operator*() only
+        if it is present.
+
+        Whether or not the window has a normal window frame depends on the flags
+        that were set when the window was created by Component::addToDesktop()
+    */
+    virtual OptionalBorderSize getFrameSizeIfPresent() const = 0;
+
     /** Returns the size of the window frame that's around this window.
         Whether or not the window has a normal window frame depends on the flags
         that were set when the window was created by Component::addToDesktop()

modules/juce_gui_basics/windows/juce_ResizableWindow.cpp

@@ -566,10 +566,12 @@ bool ResizableWindow::restoreWindowStateFromString (const String& s)
 
     if (peer != nullptr)
     {
-        peer->getFrameSize().addTo (newPos);
+        if (const auto frameSize = peer->getFrameSizeIfPresent())
+            frameSize->addTo (newPos);
     }
+
    #if JUCE_LINUX
-    else
+    if (peer == nullptr || ! peer->getFrameSizeIfPresent())
     {
         // We need to adjust for the frame size before we create a peer, as X11
         // doesn't provide this information at construction time.
@@ -580,7 +582,9 @@ bool ResizableWindow::restoreWindowStateFromString (const String& s)
                                     tokens[firstCoord + 7].getIntValue(),
                                     tokens[firstCoord + 8].getIntValue() };
 
-            frame.addTo (newPos);
+            newPos.setX (newPos.getX() - frame.getLeft());
+            newPos.setY (newPos.getY() - frame.getTop());
+
             setBounds (newPos);
         }
     }