Using Text Templates
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Example for combining wxHashMap, wxVariant to make text templates, esp. embedding wxImage in wxHTML.
#include <wx/variant.h>
#include <wx/hashmap.h>
#include <wx/fs_mem.h>
#include <wx/html/htmlwin.h>
WX_DECLARE_STRING_HASH_MAP( wxVariant , ReplaceMap );
//! Expand the given template with the replaceMap
void ExpandTemplate( wxString& templ , ReplaceMap replaceMap )
{
for( ReplaceMap::iterator it = replaceMap.begin() ; it != replaceMap.end() ; ++it )
{
wxString pattern = it->first;
wxVariant value = it->second;
// every wxVariant has a string representation
// so no need to distinguish between wxString, long, .., :^)
templ.Replace( pattern , value.MakeString() , true /* ReplaceAll */);
}
}
//! Scale originalSize to targetSize and keep ration
wxSize ScaleSizeKeepRatio( wxSize originalSize , wxSize targetSize )
{
float scaleX = ((float)targetSize.GetWidth()) / ((float)originalSize.GetWidth());
float scaleY = ((float)targetSize.GetHeight()) / ((float)originalSize.GetHeight());
float scale = wxMin( scaleX , scaleY );
return wxSize( originalSize.GetWidth() * scale , originalSize.GetHeight() * scale );
}
void MyAppFrame::HtmlTest()
{
// build the Template, with placeholder-pattern
// REMARK: could loaded from Text file too.
wxString htmlTemplate;
htmlTemplate << wxString(wxT("<html>");
htmlTemplate << wxString(wxT("<body>"));
htmlTemplate << wxString(wxT("<h1>@PAGETITLE@</h1>"));
htmlTemplate << wxString(wxT(" <center>"));
htmlTemplate << wxString(wxT(" <img width=\"@WIDTH@\" height=\"@HEIGHT@\" src=\"@IMAGE@\" >"));
htmlTemplate << wxString(wxT(" </center>"));
htmlTemplate << wxString(wxT(" <h2>Details</h2>"));
htmlTemplate << wxString(wxT(" @IMAGETITLE@ "));
htmlTemplate << wxString(wxT("</body></html>"));
// a image , e.g. generated from your code
wxImage image(700,700);
// check for existing logo.png im memoryfilesystem
wxFileSystem myfs; // contents static member of current Filesystem
if ( NULL != myfs.OpenFile(wxT("memory:logo.png")) )
wxMemoryFSHandler::RemoveFile(wxT("logo.png") );
// for accessing the (not loaded) image from the wxHTML
// we must add this to the MemoryFileSystem
wxMemoryFSHandler::AddFile(wxT("logo.png"), image , wxBITMAP_TYPE_PNG);
// max size for the image
int maxWidth = 600;
int maxHeight = 400;
// calculate the desired imageSize
wxSize imageSize = ScaleSizeKeepRatio( wxSize(image.GetWidth(), image.GetHeight()),
wxSize(maxWidth , maxHeight) );
// our replacement table
// it is a (String) Hashmap of wxVariant, the key is the variablename (@PATTERN@)
// the value is a wxVariant (a long,wxString,bool ...)
ReplaceMap replaceMap;
replaceMap[wxT("@WIDTH@")] = (long)imageSize.GetWidth();
replaceMap[wxT("@HEIGHT@")] = (long)imageSize.GetHeight();
replaceMap[wxT("@IMAGE@")] = wxT("memory:logo.png");
replaceMap[wxT("@IMAGETITLE@")] = wxT("memory:logo.png");
replaceMap[wxT("@PAGETITLE@")] = wxT("Image-Test");
// now expand the template
ExpandTemplate( htmlTemplate , replaceMap );
// code taken from the html sample
// show the expanded template in a HtmlDialog
wxDialog dlg(this, -1, _("About")));
wxBoxSizer *topsizer;
wxHtmlWindow *html;
topsizer = new wxBoxSizer(wxVERTICAL);
html = new wxHtmlWindow(&dlg, -1, wxDefaultPosition,
wxSize(380, 160), wxHW_SCROLLBAR_NEVER);
html->SetBorders(0);
html->SetPage(htmlTemplate);
html->SetSize(html->GetInternalRepresentation()->GetWidth(),
html->GetInternalRepresentation()->GetHeight());
topsizer->Add(html, 1, wxALL, 10);
topsizer->Add(new wxStaticLine(&dlg, -1), 0, wxEXPAND | wxLEFT | wxRIGHT, 10);
topsizer->Add(new wxButton(&dlg, wxID_OK, _("Ok")),
0, wxALL | wxALIGN_RIGHT, 15);
dlg.SetAutoLayout(true);
dlg.SetSizer(topsizer);
topsizer->Fit(&dlg);
dlg.Centre();
dlg.ShowModal();
}
by Sternhaus