wxWidgets/tests/html/htmprint.cpp

///////////////////////////////////////////////////////////////////////////////
// Name:        tests/html/htmprint.cpp
// Purpose:     wxHtmlPrintout tests
// Author:      Vadim Zeitlin
// Created:     2018-05-22
// Copyright:   (c) 2018 Vadim Zeitlin <vadim@wxwidgets.org>
//              (c) 2026 wxWidgets development team
///////////////////////////////////////////////////////////////////////////////

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

#include "testprec.h"

#if wxUSE_HTML
#if wxUSE_PRINTING_ARCHITECTURE

#ifndef WX_PRECOMP
    #include "wx/bitmap.h"
    #include "wx/brush.h"
    #include "wx/dcmemory.h"
    #include "wx/image.h"
#endif // WX_PRECOMP

#include "wx/display.h"
#include "wx/html/htmprint.h"

namespace
{

// Return the number of pages in the printout.
int CountPages(wxHtmlPrintout& pr)
{
    REQUIRE_NOTHROW( pr.OnPreparePrinting() );

    int pageMin = -1,
        pageMax = -1,
        selFrom = -1,
        selTo   = -1;
    REQUIRE_NOTHROW( pr.GetPageInfo(&pageMin, &pageMax, &selFrom, &selTo) );

    // This should be always the case.
    CHECK( pageMin == 1 );

    // Return the really interesting value to the caller.
    return pageMax;
}

} // anonymous namespace

TEST_CASE("wxHtmlDCRenderer::BodyBgColour", "[html][print]")
{
    const wxColour bg(0x12, 0x34, 0x56);
    wxBitmap bmp(100, 100);
    {
        wxMemoryDC dc(bmp);
        dc.SetBackground(*wxWHITE_BRUSH);
        dc.Clear();

        wxHtmlDCRenderer renderer;
        renderer.SetDC(&dc);
        renderer.SetSize(bmp.GetWidth(), bmp.GetHeight());
        renderer.SetHtmlText("<body bgcolor=\"#123456\">"
                             "<p>Hello world!</p>"
                             "</body>");
        renderer.Render(0, 0);
    }

    const wxImage image = bmp.ConvertToImage();
    const wxColour actual(image.GetRed(90, 90),
                          image.GetGreen(90, 90),
                          image.GetBlue(90, 90));
    CHECK(actual == bg);
}

TEST_CASE("wxHtmlPrintout::Pagination", "[html][print]")
{
    wxHtmlPrintout pr;

    // Pagination works in terms of printer page size, which is obtained by
    // subtracting margins from the total size and margins are expressed in
    // millimeters, so their conversion to pixels depends on DPI. To ensure
    // that we get the same results for all values of DPI, get just get rid
    // of the margins entirely (it would also be possible to adjust them by
    // the DPI-dependent factor, but it doesn't seem to be worth doing it).
    pr.SetMargins(0, 0, 0, 0, 0);

    // Ensure that the fonts are not scaled when rendering: the scale used by
    // wxHtmlPrintout::OnPreparePrinting() is the ratio of the printer and the
    // screen PPI, and SetUp() below always uses wxDisplay::GetStdPPI() for the
    // latter, so use the same value for the former to make the ratio 1.
    //
    // Note that this must be done before SetUp() which would otherwise use the
    // PPI of the DC below for the printer.
    pr.SetPPIPrinter(wxDisplay::GetStdPPI());

    wxBitmap bmp(1000, 1000);
    wxMemoryDC dc(bmp);
    REQUIRE( pr.SetUp(dc) );

    // Pagination depends on the height of the text in pixels, so the base font
    // must have a fixed size in pixels for the results to be the same on all
    // systems, whatever their DPI is. As SetStandardFonts() takes the size in
    // points, convert the size we want using the PPI of the DC we're going to
    // render on -- we can't use wxFont::GetPointSize() of a font created with
    // the fixed pixel size for this, as the conversion performed by it doesn't
    // necessarily use the same DPI, and doesn't under wxGTK, resulting in a
    // different font size and hence different number of pages here.
    //
    // We could also make the page height proportional to the DPI, but this
    // would be more complicated as we also wouldn't be able to use hardcoded
    // height attribute values in the HTML snippets below then.
    const int ppi = dc.GetPPI().y;
    REQUIRE( ppi > 0 );

    const int fontSize = 16 * 72 / ppi;
    pr.SetStandardFonts(fontSize, "Helvetica");

    // Empty or short HTML documents should be printed on a single page only.
    CHECK( CountPages(pr) == 1 );

    pr.SetHtmlText("<p>Hello world!</p>");
    CHECK( CountPages(pr) == 1 );

    // This one should be too big to fit on a single page.
    pr.SetHtmlText
       (
            "<img width=\"100\" height=\"600\" src=\"dummy\"/>"
            "<br/>"
            "<img width=\"100\" height=\"600\" src=\"dummy\"/>"
       );
    CHECK( CountPages(pr) == 2 );

    // Special case: normally images are not split, but if the image height is
    // greater than the page height, it should be.
    pr.SetHtmlText
       (
            "<img width=\"100\" height=\"2500\" src=\"dummy\"/>"
       );
    CHECK( CountPages(pr) == 3 );

    // Test explicit page breaks too.
    pr.SetHtmlText
       (
            "First page"
            "<div style=\"page-break-before:always\"/>"
            "Second page"
       );
    CHECK( CountPages(pr) == 2 );

    pr.SetHtmlText
       (
            "Something"
            "<div style=\"page-break-before:always\">"
                "<div style=\"page-break-before:always\">"
                    "<div style=\"page-break-before:always\">"
                        "whatever"
                    "</div>"
                "</div>"
            "</div>"
       );
    CHECK( CountPages(pr) == 2 );

    // Also test that forbidding page breaks inside a paragraph works: it
    // should move it entirely to the next page, resulting in one extra page
    // compared to the version without "page-break-inside: avoid".
    static const char* const text = R"(
Early in the morning on the fourteenth of the spring month of Nisan the<br>
Procurator of Judea, Pontius Pilate, in a white cloak lined with blood red,<br>
emerged with his shuffling cavalryman's walk into the arcade connecting the two<br>
wings of the palace of Herod the Great.<br>
<br>
More than anything else in the world the Procurator hated the smell of attar of<br>
roses.  The omens for the day were bad, as this scent had been haunting him<br>
since dawn.<br>
<br>
It seemed to the Procurator that the very cypresses and palms in the garden<br>
were exuding the smell of roses, that this damned stench of roses was even<br>
mingling with the smell of leather tackle and sweat from his mounted bodyguard.<br>
<br>
A haze of smoke was drifting toward the arcade across the upper courtyard of<br>
the garden, coming from the wing at the rear of the palace, the quarters of the<br>
first cohort of the XII Legion; known as the "Lightning," it had been<br>
stationed in Jerusalem since the Procurator's arrival.  The same oily perfume<br>
of roses was mixed with the acrid smoke that showed that the centuries' cooks<br>
had started to prepare breakfast<br>
<br>
"Oh, gods, what are you punishing me for?..  No, there's no doubt, I have it<br>
again, this terrible incurable pain...  hemicrania, when half the head aches...<br>
There's no cure for it, nothing helps...  I must try not to move my head..."<br>
<br>
A chair had already been placed on the mosaic floor by the fountain; without a<br>
glance around, the Procurator sat in it and stretched out his hand to one side.<br>
His secretary deferentially laid a piece of parchment in his hand.  Unable to<br>
restrain a grimace of agony, the Procurator gave a fleeting sideways look at<br>
its contents, returned the parchment to his secretary and said painfully, "The<br>
accused comes from Galilee, does he?  Was the case sent to the tetrarch?"<br>
<br>
"Yes, Procurator," replied the secretary.  "He declined to confirm the<br>
finding of the court and passed the Sanhedrin's sentence of death to you for<br>
confirmation."<br>
<br>
The Procurator's cheek twitched, and he said quietly, "Bring in the accused."<br>
)";

    pr.SetHtmlText
       (
            wxString::Format
            (
                "<img width=\"100\" height=\"500\" src=\"dummy\"/>"
                "<div>%s</div>"
                "<br/>"
                "<img width=\"100\" height=\"500\" src=\"dummy\"/>",
                text
            )
       );
    CHECK( CountPages(pr) == 2 );

    pr.SetHtmlText
       (
            wxString::Format
            (
                "<img width=\"100\" height=\"500\" src=\"dummy\"/>"
                "<div style=\"page-break-inside:avoid\">%s</div>"
                "<br/>"
                "<img width=\"100\" height=\"500\" src=\"dummy\"/>",
                text
            )
       );
    INFO("Using base font size " << fontSize);
    CHECK( CountPages(pr) == 3 );
}

#endif //wxUSE_PRINTING_ARCHITECTURE
#endif //wxUSE_HTML