layout/forms/nsGfxCheckboxControlFrame.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsGfxCheckboxControlFrame.h"
   7
   8 #include "gfxUtils.h"
   9 #include "mozilla/gfx/2D.h"
  10 #include "nsIContent.h"
  11 #include "nsCOMPtr.h"
  12 #include "nsLayoutUtils.h"
  13 #include "nsRenderingContext.h"
  14 #include "nsIDOMHTMLInputElement.h"
  15 #include "nsDisplayList.h"
  16 #include <algorithm>
  17
  18 using namespace mozilla;
  19 using namespace mozilla::gfx;
  20
  21 static void
  22 PaintCheckMark(nsIFrame* aFrame,
  23                nsRenderingContext* aCtx,
  24                const nsRect& aDirtyRect,
  25                nsPoint aPt)
  26 {
  27   nsRect rect(aPt, aFrame->GetSize());
  28   rect.Deflate(aFrame->GetUsedBorderAndPadding());
  29
  30   // Points come from the coordinates on a 7X7 unit box centered at 0,0
  31   const int32_t checkPolygonX[] = { -3, -1,  3,  3, -1, -3 };
  32   const int32_t checkPolygonY[] = { -1,  1, -3, -1,  3,  1 };
  33   const int32_t checkNumPoints = sizeof(checkPolygonX) / sizeof(int32_t);
  34   const int32_t checkSize      = 9; // 2 units of padding on either side
  35                                     // of the 7x7 unit checkmark
  36
  37   // Scale the checkmark based on the smallest dimension
  38   nscoord paintScale = std::min(rect.width, rect.height) / checkSize;
  39   nsPoint paintCenter(rect.x + rect.width  / 2,
  40                       rect.y + rect.height / 2);
  41
  42   DrawTarget* drawTarget = aCtx->GetDrawTarget();
  43   RefPtr<PathBuilder> builder = drawTarget->CreatePathBuilder();
  44   nsPoint p = paintCenter + nsPoint(checkPolygonX[0] * paintScale,
  45                                     checkPolygonY[0] * paintScale);
  46
  47   int32_t appUnitsPerDevPixel = aFrame->PresContext()->AppUnitsPerDevPixel();
  48   builder->MoveTo(NSPointToPoint(p, appUnitsPerDevPixel));
  49   for (int32_t polyIndex = 1; polyIndex < checkNumPoints; polyIndex++) {
  50     p = paintCenter + nsPoint(checkPolygonX[polyIndex] * paintScale,
  51                               checkPolygonY[polyIndex] * paintScale);
  52     builder->LineTo(NSPointToPoint(p, appUnitsPerDevPixel));
  53   }
  54   RefPtr<Path> path = builder->Finish();
  55   drawTarget->Fill(path,
  56                    ColorPattern(ToDeviceColor(aFrame->StyleColor()->mColor)));
  57 }
  58
  59 static void
  60 PaintIndeterminateMark(nsIFrame* aFrame,
  61                        nsRenderingContext* aCtx,
  62                        const nsRect& aDirtyRect,
  63                        nsPoint aPt)
  64 {
  65   DrawTarget* drawTarget = aCtx->GetDrawTarget();
  66   int32_t appUnitsPerDevPixel = aFrame->PresContext()->AppUnitsPerDevPixel();
  67
  68   nsRect rect(aPt, aFrame->GetSize());
  69   rect.Deflate(aFrame->GetUsedBorderAndPadding());
  70   rect.y += (rect.height - rect.height/4) / 2;
  71   rect.height /= 4;
  72
  73   Rect devPxRect = NSRectToSnappedRect(rect, appUnitsPerDevPixel, *drawTarget);
  74
  75   drawTarget->FillRect(devPxRect,
  76                     ColorPattern(ToDeviceColor(aFrame->StyleColor()->mColor)));
  77 }
  78
  79 //------------------------------------------------------------
  80 nsIFrame*
  81 NS_NewGfxCheckboxControlFrame(nsIPresShell* aPresShell,
  82                               nsStyleContext* aContext)
  83 {
  84   return new (aPresShell) nsGfxCheckboxControlFrame(aContext);
  85 }
  86
  87 NS_IMPL_FRAMEARENA_HELPERS(nsGfxCheckboxControlFrame)
  88
  89
  90 //------------------------------------------------------------
  91 // Initialize GFX-rendered state
  92 nsGfxCheckboxControlFrame::nsGfxCheckboxControlFrame(nsStyleContext* aContext)
  93 : nsFormControlFrame(aContext)
  94 {
  95 }
  96
  97 nsGfxCheckboxControlFrame::~nsGfxCheckboxControlFrame()
  98 {
  99 }
 100
 101 #ifdef ACCESSIBILITY
 102 a11y::AccType
 103 nsGfxCheckboxControlFrame::AccessibleType()
 104 {
 105   return a11y::eHTMLCheckboxType;
 106 }
 107 #endif
 108
 109 //------------------------------------------------------------
 110 void
 111 nsGfxCheckboxControlFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 112                                             const nsRect&           aDirtyRect,
 113                                             const nsDisplayListSet& aLists)
 114 {
 115   nsFormControlFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
 116
 117   // Get current checked state through content model.
 118   if ((!IsChecked() && !IsIndeterminate()) || !IsVisibleForPainting(aBuilder))
 119     return;   // we're not checked or not visible, nothing to paint.
 120
 121   if (IsThemed())
 122     return; // No need to paint the checkmark. The theme will do it.
 123
 124   aLists.Content()->AppendNewToTop(new (aBuilder)
 125     nsDisplayGeneric(aBuilder, this,
 126                      IsIndeterminate()
 127                      ? PaintIndeterminateMark : PaintCheckMark,
 128                      "CheckedCheckbox",
 129                      nsDisplayItem::TYPE_CHECKED_CHECKBOX));
 130 }
 131
 132 //------------------------------------------------------------
 133 bool
 134 nsGfxCheckboxControlFrame::IsChecked()
 135 {
 136   nsCOMPtr<nsIDOMHTMLInputElement> elem(do_QueryInterface(mContent));
 137   bool retval = false;
 138   elem->GetChecked(&retval);
 139   return retval;
 140 }
 141
 142 bool
 143 nsGfxCheckboxControlFrame::IsIndeterminate()
 144 {
 145   nsCOMPtr<nsIDOMHTMLInputElement> elem(do_QueryInterface(mContent));
 146   bool retval = false;
 147   elem->GetIndeterminate(&retval);
 148   return retval;
 149 }