Restore generic GetPartialTextExtents() version use in wxGTK and wxMSW.

Non-wxWindowDC-derived wxDC classes in wxGTK, such as wxGtkPrinterDCImpl, have
to fall back on the generic implementation of GetPartialTextExtents() as Pango
version can't be used with them.

This fixes a crash due to using NULL Pango layout when printing wxRichTextCtrl
in wxGTK.

Closes #14847.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73017 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/textmeasurecmn.cpp

@@ -198,3 +198,82 @@ bool wxTextMeasureBase::GetPartialTextExtents(const wxString& text,
 
     return DoGetPartialTextExtents(text, widths, scaleX);
 }
+
+// ----------------------------------------------------------------------------
+// Generic and inefficient DoGetPartialTextExtents() implementation.
+// ----------------------------------------------------------------------------
+
+// Each element of the widths array will be the width of the string up to and
+// including the corresponding character in text.  This is the generic
+// implementation, the port-specific classes should do this with native APIs
+// if available and if faster.  Note: pango_layout_index_to_pos is much slower
+// than calling GetTextExtent!!
+
+#define FWC_SIZE 256
+
+class FontWidthCache
+{
+public:
+    FontWidthCache() : m_scaleX(1), m_widths(NULL) { }
+    ~FontWidthCache() { delete []m_widths; }
+
+    void Reset()
+    {
+        if ( !m_widths )
+            m_widths = new int[FWC_SIZE];
+
+        memset(m_widths, 0, sizeof(int)*FWC_SIZE);
+    }
+
+    wxFont m_font;
+    double m_scaleX;
+    int *m_widths;
+};
+
+static FontWidthCache s_fontWidthCache;
+
+bool wxTextMeasureBase::DoGetPartialTextExtents(const wxString& text,
+                                                wxArrayInt& widths,
+                                                double scaleX)
+{
+    int totalWidth = 0;
+
+    // reset the cache if font or horizontal scale have changed
+    if ( !s_fontWidthCache.m_widths ||
+         !wxIsSameDouble(s_fontWidthCache.m_scaleX, scaleX) ||
+         (s_fontWidthCache.m_font != *m_font) )
+    {
+        s_fontWidthCache.Reset();
+        s_fontWidthCache.m_font = *m_font;
+        s_fontWidthCache.m_scaleX = scaleX;
+    }
+
+    // Calculate the position of each character based on the widths of
+    // the previous characters. This is inexact for not fixed fonts.
+    int n = 0;
+    for ( wxString::const_iterator it = text.begin();
+          it != text.end();
+          ++it )
+    {
+        const wxChar c = *it;
+        unsigned int c_int = (unsigned int)c;
+
+        int w;
+        if ((c_int < FWC_SIZE) && (s_fontWidthCache.m_widths[c_int] != 0))
+        {
+            w = s_fontWidthCache.m_widths[c_int];
+        }
+        else
+        {
+            DoGetTextExtent(c, &w, NULL);
+            if (c_int < FWC_SIZE)
+                s_fontWidthCache.m_widths[c_int] = w;
+        }
+
+        totalWidth += w;
+        widths[n++] = totalWidth;
+    }
+
+    return true;
+}
+

src/generic/textmeasure.cpp

@@ -59,78 +59,11 @@ void wxTextMeasure::DoGetTextExtent(const wxString& string,
     //else: we already asserted in the ctor, don't do it any more
 }
 
-// Each element of the widths array will be the width of the string up to and
-// including the corresponding character in text.  This is the generic
-// implementation, the port-specific classes should do this with native APIs
-// if available and if faster.  Note: pango_layout_index_to_pos is much slower
-// than calling GetTextExtent!!
-
-#define FWC_SIZE 256
-
-class FontWidthCache
-{
-public:
-    FontWidthCache() : m_scaleX(1), m_widths(NULL) { }
-    ~FontWidthCache() { delete []m_widths; }
-
-    void Reset()
-    {
-        if ( !m_widths )
-            m_widths = new int[FWC_SIZE];
-
-        memset(m_widths, 0, sizeof(int)*FWC_SIZE);
-    }
-
-    wxFont m_font;
-    double m_scaleX;
-    int *m_widths;
-};
-
-static FontWidthCache s_fontWidthCache;
-
 bool wxTextMeasure::DoGetPartialTextExtents(const wxString& text,
                                             wxArrayInt& widths,
                                             double scaleX)
 {
-    int totalWidth = 0;
+    return wxTextMeasureBase::DoGetPartialTextExtents(text, widths, scaleX);
-
-    // reset the cache if font or horizontal scale have changed
-    if ( !s_fontWidthCache.m_widths ||
-         !wxIsSameDouble(s_fontWidthCache.m_scaleX, scaleX) ||
-         (s_fontWidthCache.m_font != *m_font) )
-    {
-        s_fontWidthCache.Reset();
-        s_fontWidthCache.m_font = *m_font;
-        s_fontWidthCache.m_scaleX = scaleX;
-    }
-
-    // Calculate the position of each character based on the widths of
-    // the previous characters. This is inexact for not fixed fonts.
-    int n = 0;
-    for ( wxString::const_iterator it = text.begin();
-          it != text.end();
-          ++it )
-    {
-        const wxChar c = *it;
-        unsigned int c_int = (unsigned int)c;
-
-        int w;
-        if ((c_int < FWC_SIZE) && (s_fontWidthCache.m_widths[c_int] != 0))
-        {
-            w = s_fontWidthCache.m_widths[c_int];
-        }
-        else
-        {
-            DoGetTextExtent(c, &w, NULL);
-            if (c_int < FWC_SIZE)
-                s_fontWidthCache.m_widths[c_int] = w;
-        }
-
-        totalWidth += w;
-        widths[n++] = totalWidth;
-    }
-
-    return true;
 }
 
 #endif // wxUSE_GENERIC_TEXTMEASURE

src/gtk/textmeasure.cpp

@@ -165,8 +165,11 @@ void wxTextMeasure::DoGetTextExtent(const wxString& string,
 
 bool wxTextMeasure::DoGetPartialTextExtents(const wxString& text,
                                             wxArrayInt& widths,
-                                            double WXUNUSED(scaleX))
+                                            double scaleX)
 {
+    if ( !m_layout )
+        return wxTextMeasureBase::DoGetPartialTextExtents(text, widths, scaleX);
+
     // Set layout's text
     const wxCharBuffer dataUTF8 = wxGTK_CONV_FONT(text, GetFont());
     if ( !dataUTF8 )

src/msw/textmeasure.cpp

@@ -150,8 +150,11 @@ void wxTextMeasure::DoGetTextExtent(const wxString& string,
 
 bool wxTextMeasure::DoGetPartialTextExtents(const wxString& text,
                                             wxArrayInt& widths,
-                                            double WXUNUSED(scaleX))
+                                            double scaleX)
 {
+    if ( !m_hdc )
+        return wxTextMeasureBase::DoGetPartialTextExtents(text, widths, scaleX);
+
     static int maxLenText = -1;
     static int maxWidth = -1;