Properly handle margin settings in WinCairo.

https://bugs.webkit.org/show_bug.cgi?id=34545

Reviewed by Adam Roben.

* WebFrame.cpp:
(scaleFactor): Require the margin information as an input
  parameter, and use them when computing the scaling factor.
(WebFrame::drawHeader): Pass margin size to scaleFactor.
(WebFrame::drawFooter): Pass margin size to scaleFactor.
(WebFrame::spoolPage):
  1. Pass margin size to scaleFactor.
  2. Recognize that the return value of printerMarginRect is
     already in device units, and therefore scale it so that
     the Cairo drawing is correct.
  3. Remove scaling call for margins in GDI code, as it is
     already in scaled units.



git-svn-id: svn://svn.chromium.org/blink/trunk@54356 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/WebKit/win/ChangeLog

+2010-02-04  Brent Fulgham  <bfulgham@webkit.org>
+
+        Reviewed by Adam Roben.
+
+        Properly handle margin settings in WinCairo.
+        https://bugs.webkit.org/show_bug.cgi?id=34545
+
+        * WebFrame.cpp:
+        (scaleFactor): Require the margin information as an input
+          parameter, and use them when computing the scaling factor.
+        (WebFrame::drawHeader): Pass margin size to scaleFactor.
+        (WebFrame::drawFooter): Pass margin size to scaleFactor.
+        (WebFrame::spoolPage):
+          1. Pass margin size to scaleFactor.
+          2. Recognize that the return value of printerMarginRect is
+             already in device units, and therefore scale it so that
+             the Cairo drawing is correct.
+          3. Remove scaling call for margins in GDI code, as it is
+             already in scaled units.
+
 2010-02-03  Brian Weinstein  <bweinstein@apple.com>
 
         Reviewed by Steve Falkenburg.

third_party/WebKit/WebKit/win/WebFrame.cpp

@@ -2018,11 +2018,17 @@ void WebFrame::spoolPage(PlatformGraphicsContext* pctx, GraphicsContext* spoolCt
     CGContextRestoreGState(pctx);
 }
 #elif PLATFORM(CAIRO)
-static float scaleFactor(HDC printDC, const IntRect& pageRect)
+static float scaleFactor(HDC printDC, const IntRect& marginRect, const IntRect& pageRect)
 {
     const IntRect& printRect = printerRect(printDC);
 
-    float scale = static_cast<float>(printRect.width()) / static_cast<float>(pageRect.width());
+    IntRect adjustedRect = IntRect(
+        printRect.x() + marginRect.x(),
+        printRect.y() + marginRect.y(),
+        printRect.width() - marginRect.x() - marginRect.right(),
+        printRect.height() - marginRect.y() - marginRect.bottom());
+
+    float scale = static_cast<float>(adjustedRect.width()) / static_cast<float>(pageRect.width());
     if (!scale)
        scale = 1.0;
 
@@ -2038,8 +2044,9 @@ static HDC hdcFromContext(PlatformGraphicsContext* pctx)
 void WebFrame::drawHeader(PlatformGraphicsContext* pctx, IWebUIDelegate* ui, const IntRect& pageRect, float headerHeight)
 {
     HDC hdc = hdcFromContext(pctx);
+    const IntRect& marginRect = printerMarginRect(hdc);
 
-    const float scale = scaleFactor(hdc, pageRect);
+    const float scale = scaleFactor(hdc, marginRect, pageRect);
     int x = static_cast<int>(scale * pageRect.x());
     int y = 0;
     RECT headerRect = {x, y, x + static_cast<int>(scale * pageRect.width()), y + static_cast<int>(scale * headerHeight)};
@@ -2050,8 +2057,9 @@ void WebFrame::drawHeader(PlatformGraphicsContext* pctx, IWebUIDelegate* ui, con
 void WebFrame::drawFooter(PlatformGraphicsContext* pctx, IWebUIDelegate* ui, const IntRect& pageRect, UINT page, UINT pageCount, float headerHeight, float footerHeight)
 {
     HDC hdc = hdcFromContext(pctx);
+    const IntRect& marginRect = printerMarginRect(hdc);
 
-    const float scale = scaleFactor(hdc, pageRect);
+    const float scale = scaleFactor(hdc, marginRect, pageRect);
     int x = static_cast<int>(scale * pageRect.x());
     int y = static_cast<int>(scale * max(static_cast<int>(headerHeight) + pageRect.height(), m_pageHeight-static_cast<int>(footerHeight)));
     RECT footerRect = {x, y, x + static_cast<int>(scale * pageRect.width()), y + static_cast<int>(scale * footerHeight)};
@@ -2064,24 +2072,27 @@ void WebFrame::spoolPage(PlatformGraphicsContext* pctx, GraphicsContext* spoolCt
     Frame* coreFrame = core(this);
 
     const IntRect& pageRect = m_pageRects[page];
-    IntRect marginRect = printerMarginRect(printDC);
+    const IntRect& marginRect = printerMarginRect(printDC);
 
     cairo_save(pctx);
-    float scale = scaleFactor(printDC, pageRect);
+    float scale = scaleFactor(printDC, marginRect, pageRect);
     cairo_scale(pctx, scale, scale);
 
-    cairo_translate(pctx, -pageRect.x() + marginRect.x(), -pageRect.y() + marginRect.y() + headerHeight);
+    IntRect cairoMarginRect (marginRect);
+    cairoMarginRect.scale (1 / scale);
+
+    cairo_translate(pctx, -pageRect.x() + cairoMarginRect.x(), -pageRect.y() + cairoMarginRect.y() + headerHeight);
     coreFrame->view()->paintContents(spoolCtx, pageRect);
 
-    cairo_translate(pctx, pageRect.x() - marginRect.x(), pageRect.y() - marginRect.y() - headerHeight);
+    cairo_translate(pctx, pageRect.x() - cairoMarginRect.x(), pageRect.y() - cairoMarginRect.y() - headerHeight);
 
     XFORM originalWorld;
     ::GetWorldTransform(printDC, &originalWorld);
 
     // Position world transform to account for margin
     XFORM newWorld = originalWorld;
-    newWorld.eDx = scale * marginRect.x();
-    newWorld.eDy = scale * marginRect.y();
+    newWorld.eDx = marginRect.x();
+    newWorld.eDy = marginRect.y();
 
     ::SetWorldTransform(printDC, &newWorld);