Seperate initialization of OutputDevice instance

I have split OutputDevice::ImplInitGraphics() from
OutputDevice::ImplGetGraphics(). In future, we need to further
seperate out this initialization function into it's own seperate
classes. Note that ImplGetGraphics still initializes if mpGraphics
is not set.

Change-Id: I17d4778f735aa9d03bf9b37079a9d695bf95866b
Reviewed-on: https://gerrit.libreoffice.org/7777Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

include/vcl/outdev.hxx

@@ -359,9 +359,18 @@ public:
 
     /** Get the graphic context that the output device uses to draw on.
 
+     If no graphics device exists, then initialize it.
+
      @returns SalGraphics instance.
      */
-    SAL_DLLPRIVATE SalGraphics* ImplGetGraphics() const;
+    SAL_DLLPRIVATE SalGraphics const *ImplGetGraphics() const;
+    SAL_DLLPRIVATE SalGraphics* ImplGetGraphics();
+
+    /** Initialize the graphics device that the output device uses to draw on.
+
+     @returns true if was able to initialize the graphics device, false otherwise.
+     */
+    SAL_DLLPRIVATE bool         ImplInitGraphics() const;
 
     /** Release the graphics device, and remove it from the graphics device
      list.

vcl/source/gdi/outdev.cxx

@@ -183,7 +183,7 @@ bool OutputDevice::ImplSelectClipRegion( const Region& rRegion, SalGraphics* pGr
     if( !pGraphics )
     {
         if( !mpGraphics )
-            if( !ImplGetGraphics() )
+            if( !ImplInitGraphics() )
                 return false;
         pGraphics = mpGraphics;
     }
@@ -520,12 +520,39 @@ void    OutputDevice::ReMirror( Region &rRegion ) const
 
 }
 
-SalGraphics* OutputDevice::ImplGetGraphics() const
+SalGraphics* OutputDevice::ImplGetGraphics()
 {
     DBG_TESTSOLARMUTEX();
 
-    if ( mpGraphics )
-        return mpGraphics;
+    if ( !mpGraphics )
+    {
+        if ( !ImplInitGraphics() )
+        {
+            SAL_WARN("vcl", "No mpGraphics set");
+        }
+    }
+
+    return mpGraphics;
+}
+
+SalGraphics const *OutputDevice::ImplGetGraphics() const
+{
+    DBG_TESTSOLARMUTEX();
+
+    if ( !mpGraphics )
+    {
+        if ( !ImplInitGraphics() )
+        {
+            SAL_WARN("vcl", "No mpGraphics set");
+        }
+    }
+
+    return mpGraphics;
+}
+
+bool OutputDevice::ImplInitGraphics() const
+{
+    DBG_TESTSOLARMUTEX();
 
     mbInitLineColor     = true;
     mbInitFillColor     = true;
@@ -534,6 +561,8 @@ SalGraphics* OutputDevice::ImplGetGraphics() const
     mbInitClipRegion    = true;
 
     ImplSVData* pSVData = ImplGetSVData();
+
+    // TODO: move this out of OutputDevice and into subclasses
     if ( meOutDevType == OUTDEV_WINDOW )
     {
         Window* pWindow = (Window*)this;
@@ -667,7 +696,7 @@ SalGraphics* OutputDevice::ImplGetGraphics() const
         mpGraphics->setAntiAliasB2DDraw(mnAntialiasing & ANTIALIASING_ENABLE_B2DDRAW);
     }
 
-    return mpGraphics;
+    return mpGraphics ? true : false;
 }
 
 void OutputDevice::ImplReleaseGraphics( bool bRelease )