detect horizontal overflow in wxHtmlPrintout and warn the user about it

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@59862 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -514,6 +514,8 @@ All (GUI):
 - Add support for wxSP_WRAP in the generic version of wxSpinCtrlDouble.
 - Add alignment flags support to wxSpinCtrl[Double] (Andrew Radke).
 - Added wxGetSelectedChoices() replacing wxGetMultipleChoices() (Kolya Kosenko).
+- Check whether document fits into page horizontally in wxHtmlPrintout, see the
+  new CheckFit() method for more information.
 
 wxGTK:
 

include/wx/html/htmprint.h

@@ -80,9 +80,12 @@ public:
     int Render(int x, int y, wxArrayInt& known_pagebreaks, int from = 0,
                int dont_render = false, int to = INT_MAX);
 
+    // returns total width of the html document
+    int GetTotalWidth() const;
+
     // returns total height of the html document
     // (compare Render's return value with this)
-    int GetTotalHeight();
+    int GetTotalHeight() const;
 
 private:
     wxDC *m_DC;
@@ -169,6 +172,18 @@ public:
     static void CleanUpStatics();
 
 private:
+    // this function is called by the base class OnPreparePrinting()
+    // implementation and by default checks whether the document fits into
+    // pageArea horizontally and warns the user if it does not, giving him
+    // the possibility to cancel printing in this case
+    //
+    // you may override it to either suppress this check if truncation of the
+    // HTML being printed is acceptable or, on the contrary, add more checks to
+    // it, e.g. for the fit in the vertical direction if the document should
+    // always appear on a single page
+    //
+    // return true if printing should go ahead or false to cancel it
+    virtual bool CheckFit(const wxSize& pageArea, const wxSize& docArea) const;
 
     void RenderPage(wxDC *dc, int page);
             // renders one page into dc

interface/wx/html/htmprint.h

@@ -25,12 +25,28 @@ public:
     wxHtmlDCRenderer();
 
     /**
-        Returns the height of the HTML text. This is important if area height
+        Returns the width of the HTML text in pixels.
-        (see wxHtmlDCRenderer::SetSize) is smaller that total height and thus
+
-        the page cannot fit into it. In that case you're supposed to call
+        This can be compared with the width parameter of SetSize() to check if
-        Render() as long as its return value is smaller than GetTotalHeight()'s.
+        the document being printed fits into the page boundary.
+
+        @see GetTotalHeight()
+
+        @since 2.9.0
+     */
+    int GetTotalWidth() const;
+
+    /**
+        Returns the height of the HTML text in pixels.
+
+        This is important if area height (see wxHtmlDCRenderer::SetSize) is
+        smaller that total height and thus the page cannot fit into it. In that
+        case you're supposed to call Render() as long as its return value is
+        smaller than GetTotalHeight()'s.
+
+        @see GetTotalWidth()
     */
-    int GetTotalHeight();
+    int GetTotalHeight() const;
 
     /**
         Renders HTML text to the DC.
@@ -245,6 +261,29 @@ public:
         Sets the parent window for dialogs.
     */
     void SetParentWindow(wxWindow* window);
+
+private:
+    /**
+        Check whether the document fits into the page area.
+
+        This function is called by the base class OnPreparePrinting()
+        implementation and by default checks whether the document fits into
+        @a pageArea horizontally and warns the user if it does not, giving him
+        the possibility to cancel printing in this case (presumably in order to
+        change some layout options and retry it again).
+
+        You may override it to either suppress this check if truncation of the
+        HTML being printed is acceptable or, on the contrary, add more checks to
+        it, e.g. for the fit in the vertical direction if the document should
+        always appear on a single page.
+
+        @return
+            @true if wxHtmlPrintout should continue or @false to cancel
+            printing.
+
+        @since 2.9.0
+     */
+    virtual bool CheckFit(const wxSize& pageArea, const wxSize& docArea) const;
 };
 
 

src/html/htmprint.cpp

@@ -150,11 +150,14 @@ int wxHtmlDCRenderer::Render(int x, int y,
     else return GetTotalHeight();
 }
 
-
+int wxHtmlDCRenderer::GetTotalWidth() const
-int wxHtmlDCRenderer::GetTotalHeight()
 {
-    if (m_Cells) return m_Cells->GetHeight();
+    return m_Cells ? m_Cells->GetWidth() : 0;
-    else return 0;
+}
+
+int wxHtmlDCRenderer::GetTotalHeight() const
+{
+    return m_Cells ? m_Cells->GetHeight() : 0;
 }
 
 
@@ -197,6 +200,40 @@ void wxHtmlPrintout::AddFilter(wxHtmlFilter *filter)
     m_Filters.Append(filter);
 }
 
+bool
+wxHtmlPrintout::CheckFit(const wxSize& pageArea, const wxSize& docArea) const
+{
+    if ( docArea.x > pageArea.x )
+    {
+        wxMessageDialog
+            dlg
+            (
+                NULL,
+                wxString::Format
+                (
+                 _("The document \"%s\" doesn't fit on the page "
+                   "horizontally and will be truncated if printed.\n"
+                   "\n"
+                   "Would you like to proceed with printing it nevertheless?"),
+                 GetTitle()
+                ),
+                _("Printing"),
+                wxYES_NO | wxNO_DEFAULT | wxICON_QUESTION
+            );
+        dlg.SetExtendedMessage
+            (
+                _("If possible, try changing the layout parameters to "
+                  "make the printout more narrow")
+            );
+        dlg.SetYesNoLabels(_("&Print"), _("&Cancel"));
+
+        if ( dlg.ShowModal() != wxYES )
+            return false;
+    }
+
+    return true;
+}
+
 void wxHtmlPrintout::OnPreparePrinting()
 {
     int pageWidth, pageHeight, mm_w, mm_h, scr_w, scr_h, dc_w, dc_h;
@@ -248,14 +285,27 @@ void wxHtmlPrintout::OnPreparePrinting()
 
     /* prepare main renderer: */
     m_Renderer->SetDC(GetDC(), (double)ppiPrinterY / (double)ppiScreenY);
-    m_Renderer->SetSize((int) (ppmm_h * (mm_w - m_MarginLeft - m_MarginRight)),
+
-                          (int) (ppmm_v * (mm_h - m_MarginTop - m_MarginBottom) -
+    const int printAreaW = int(ppmm_h * (mm_w - m_MarginLeft - m_MarginRight));
-                          m_FooterHeight - m_HeaderHeight -
+    int printAreaH = int(ppmm_v * (mm_h - m_MarginTop - m_MarginBottom));
-                          ((m_HeaderHeight == 0) ? 0 : m_MarginSpace * ppmm_v) -
+    if ( m_HeaderHeight )
-                          ((m_FooterHeight == 0) ? 0 : m_MarginSpace * ppmm_v)
+        printAreaH -= m_HeaderHeight + m_MarginSpace * ppmm_v;
-                          ));
+    if ( m_FooterHeight )
+        printAreaH -= m_FooterHeight + m_MarginSpace * ppmm_v;
+
+    m_Renderer->SetSize(printAreaW, printAreaH);
     m_Renderer->SetHtmlText(m_Document, m_BasePath, m_BasePathIsDir);
-    CountPages();
+
+    if ( CheckFit(wxSize(printAreaW, printAreaH),
+                  wxSize(m_Renderer->GetTotalWidth(),
+                         m_Renderer->GetTotalHeight())) )
+    {
+        // do paginate the document
+        CountPages();
+    }
+    //else: if we don't call CountPages() m_PageBreaks remains empty and our
+    //      GetPageInfo() will return 0 as max page and so nothing will be
+    //      printed
 }
 
 bool wxHtmlPrintout::OnBeginDocument(int startPage, int endPage)