The Tor Browser: layout/xul/nsScrollBoxObject.cpp@925c144e1f1f (annotated)

layout/xul/nsScrollBoxObject.cpp@925c144e1f1f (annotated)

layout/xul/nsScrollBoxObject.cpp

Fri, 16 Jan 2015 18:13:44 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Fri, 16 Jan 2015 18:13:44 +0100
branch: TOR_BUG_9701
changeset 14: 925c144e1f1f
permissions: -rw-r--r--

Integrate suggestion from review to improve consistency with existing code.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "nsCOMPtr.h"
 #include "nsIScrollBoxObject.h"
 #include "nsBoxObject.h"
 #include "nsIPresShell.h"
 #include "nsIContent.h"
 #include "nsIDOMElement.h"
 #include "nsPresContext.h"
 #include "nsIFrame.h"
 #include "nsIScrollableFrame.h"
 using namespace mozilla;
 class nsScrollBoxObject : public nsIScrollBoxObject, public nsBoxObject
 {
 public:
   NS_DECL_ISUPPORTS_INHERITED
   NS_DECL_NSISCROLLBOXOBJECT
   nsScrollBoxObject();
   virtual ~nsScrollBoxObject();
   virtual nsIScrollableFrame* GetScrollFrame() {
     return do_QueryFrame(GetFrame(false));
   }
   /* additional members */
 };
 /* Implementation file */
 NS_INTERFACE_MAP_BEGIN(nsScrollBoxObject)
   NS_INTERFACE_MAP_ENTRY(nsIScrollBoxObject)
 NS_INTERFACE_MAP_END_INHERITING(nsBoxObject)
 NS_IMPL_ADDREF_INHERITED(nsScrollBoxObject, nsBoxObject)
 NS_IMPL_RELEASE_INHERITED(nsScrollBoxObject, nsBoxObject)
 nsScrollBoxObject::nsScrollBoxObject()
 {
   /* member initializers and constructor code */
 }
 nsScrollBoxObject::~nsScrollBoxObject()
 {
   /* destructor code */
 }
 /* void scrollTo (in long x, in long y); */
 NS_IMETHODIMP nsScrollBoxObject::ScrollTo(int32_t x, int32_t y)
 {
   nsIScrollableFrame* sf = GetScrollFrame();
   if (!sf)
     return NS_ERROR_FAILURE;
   sf->ScrollToCSSPixels(CSSIntPoint(x, y));
   return NS_OK;
 }
 /* void scrollBy (in long dx, in long dy); */
 NS_IMETHODIMP nsScrollBoxObject::ScrollBy(int32_t dx, int32_t dy)
 {
   int32_t x, y;
   nsresult rv = GetPosition(&x, &y);
   if (NS_FAILED(rv))
     return rv;
   return ScrollTo(x + dx, y + dy);
 }
 /* void scrollByLine (in long dlines); */
 NS_IMETHODIMP nsScrollBoxObject::ScrollByLine(int32_t dlines)
 {
   nsIScrollableFrame* sf = GetScrollFrame();
   if (!sf)
     return NS_ERROR_FAILURE;
   sf->ScrollBy(nsIntPoint(0, dlines), nsIScrollableFrame::LINES,
                nsIScrollableFrame::SMOOTH);
   return NS_OK;
 }
 // XUL <scrollbox> elements have a single box child element.
 // Get a pointer to that box.
 // Note that now that the <scrollbox> is just a regular box
 // with 'overflow:hidden', the boxobject's frame is an nsXULScrollFrame,
 // the <scrollbox>'s box frame is the scrollframe's "scrolled frame", and
 // the <scrollbox>'s child box is a child of that.
 static nsIFrame* GetScrolledBox(nsBoxObject* aScrollBox) {
   nsIFrame* frame = aScrollBox->GetFrame(false);
   if (!frame)
     return nullptr;
   nsIScrollableFrame* scrollFrame = do_QueryFrame(frame);
   if (!scrollFrame) {
     NS_WARNING("nsIScrollBoxObject attached to something that's not a scroll frame!");
     return nullptr;
   }
   nsIFrame* scrolledFrame = scrollFrame->GetScrolledFrame();
   if (!scrolledFrame)
     return nullptr;
   return scrolledFrame->GetChildBox();
 }
 /* void scrollByIndex (in long dindexes); */
 NS_IMETHODIMP nsScrollBoxObject::ScrollByIndex(int32_t dindexes)
 {
     nsIScrollableFrame* sf = GetScrollFrame();
     if (!sf)
        return NS_ERROR_FAILURE;
     nsIFrame* scrolledBox = GetScrolledBox(this);
     if (!scrolledBox)
        return NS_ERROR_FAILURE;
     nsRect rect;
     // now get the scrolled boxes first child.
     nsIFrame* child = scrolledBox->GetChildBox();
     bool horiz = scrolledBox->IsHorizontal();
     nsPoint cp = sf->GetScrollPosition();
     nscoord diff = 0;
     int32_t curIndex = 0;
     bool isLTR = scrolledBox->IsNormalDirection();
     int32_t frameWidth = 0;
     if (!isLTR && horiz) {
       GetWidth(&frameWidth);
       nsCOMPtr<nsIPresShell> shell = GetPresShell(false);
       if (!shell) {
         return NS_ERROR_UNEXPECTED;
       }
       frameWidth = nsPresContext::CSSPixelsToAppUnits(frameWidth);
     }
     // first find out what index we are currently at
     while(child) {
       rect = child->GetRect();
       if (horiz) {
         // In the left-to-right case we break from the loop when the center of
         // the current child rect is greater than the scrolled position of
         // the left edge of the scrollbox
         // In the right-to-left case we break when the center of the current
         // child rect is less than the scrolled position of the right edge of
         // the scrollbox.
         diff = rect.x + rect.width/2; // use the center, to avoid rounding errors
         if ((isLTR && diff > cp.x) ||
             (!isLTR && diff < cp.x + frameWidth)) {
           break;
         }
       } else {
         diff = rect.y + rect.height/2;// use the center, to avoid rounding errors
         if (diff > cp.y) {
           break;
         }
       }
       child = child->GetNextBox();
       curIndex++;
     }
     int32_t count = 0;
     if (dindexes == 0)
        return NS_OK;
     if (dindexes > 0) {
       while(child) {
         child = child->GetNextBox();
         if (child)
           rect = child->GetRect();
         count++;
         if (count >= dindexes)
           break;
       }
    } else if (dindexes < 0) {
       child = scrolledBox->GetChildBox();
       while(child) {
         rect = child->GetRect();
         if (count >= curIndex + dindexes)
           break;
         count++;
         child = child->GetNextBox();
       }
    }
    nscoord csspixel = nsPresContext::CSSPixelsToAppUnits(1);
    if (horiz) {
        // In the left-to-right case we scroll so that the left edge of the
        // selected child is scrolled to the left edge of the scrollbox.
        // In the right-to-left case we scroll so that the right edge of the
        // selected child is scrolled to the right edge of the scrollbox.
        nsPoint pt(isLTR ? rect.x : rect.x + rect.width - frameWidth,
                   cp.y);
        // Use a destination range that ensures the left edge (or right edge,
        // for RTL) will indeed be visible. Also ensure that the top edge
        // is visible.
        nsRect range(pt.x, pt.y, csspixel, 0);
        if (isLTR) {
          range.x -= csspixel;
        }
        sf->ScrollTo(pt, nsIScrollableFrame::INSTANT, &range);
    } else {
        // Use a destination range that ensures the top edge will be visible.
        nsRect range(cp.x, rect.y - csspixel, 0, csspixel);
        sf->ScrollTo(nsPoint(cp.x, rect.y), nsIScrollableFrame::INSTANT, &range);
    }
    return NS_OK;
 }
 /* void scrollToLine (in long line); */
 NS_IMETHODIMP nsScrollBoxObject::ScrollToLine(int32_t line)
 {
   nsIScrollableFrame* sf = GetScrollFrame();
   if (!sf)
      return NS_ERROR_FAILURE;
   nscoord y = sf->GetLineScrollAmount().height * line;
   nsRect range(0, y - nsPresContext::CSSPixelsToAppUnits(1),
 , nsPresContext::CSSPixelsToAppUnits(1));
   sf->ScrollTo(nsPoint(0, y), nsIScrollableFrame::INSTANT, &range);
   return NS_OK;
 }
 /* void scrollToElement (in nsIDOMElement child); */
 NS_IMETHODIMP nsScrollBoxObject::ScrollToElement(nsIDOMElement *child)
 {
     NS_ENSURE_ARG_POINTER(child);
     nsCOMPtr<nsIPresShell> shell = GetPresShell(false);
     if (!shell) {
       return NS_ERROR_UNEXPECTED;
     }
     nsCOMPtr<nsIContent> content = do_QueryInterface(child);
     shell->ScrollContentIntoView(content,
                                  nsIPresShell::ScrollAxis(
                                    nsIPresShell::SCROLL_TOP,
                                    nsIPresShell::SCROLL_ALWAYS),
                                  nsIPresShell::ScrollAxis(
                                    nsIPresShell::SCROLL_LEFT,
                                    nsIPresShell::SCROLL_ALWAYS),
                                  nsIPresShell::SCROLL_FIRST_ANCESTOR_ONLY |
                                  nsIPresShell::SCROLL_OVERFLOW_HIDDEN);
     return NS_OK;
 }
 /* void scrollToIndex (in long index); */
 NS_IMETHODIMP nsScrollBoxObject::ScrollToIndex(int32_t index)
 {
     return NS_ERROR_NOT_IMPLEMENTED;
 }
 /* void getPosition (out long x, out long y); */
 NS_IMETHODIMP nsScrollBoxObject::GetPosition(int32_t *x, int32_t *y)
 {
   nsIScrollableFrame* sf = GetScrollFrame();
   if (!sf)
      return NS_ERROR_FAILURE;
   CSSIntPoint pt = sf->GetScrollPositionCSSPixels();
   *x = pt.x;
   *y = pt.y;
   return NS_OK;
 }
 /* void getScrolledSize (out long width, out long height); */
 NS_IMETHODIMP nsScrollBoxObject::GetScrolledSize(int32_t *width, int32_t *height)
 {
     nsIFrame* scrolledBox = GetScrolledBox(this);
     if (!scrolledBox)
         return NS_ERROR_FAILURE;
     nsRect scrollRect = scrolledBox->GetRect();
     *width  = nsPresContext::AppUnitsToIntCSSPixels(scrollRect.width);
     *height = nsPresContext::AppUnitsToIntCSSPixels(scrollRect.height);
     return NS_OK;
 }
 /* void ensureElementIsVisible (in nsIDOMElement child); */
 NS_IMETHODIMP nsScrollBoxObject::EnsureElementIsVisible(nsIDOMElement *child)
 {
     NS_ENSURE_ARG_POINTER(child);
     nsCOMPtr<nsIPresShell> shell = GetPresShell(false);
     if (!shell) {
       return NS_ERROR_UNEXPECTED;
     }
     nsCOMPtr<nsIContent> content = do_QueryInterface(child);
     shell->ScrollContentIntoView(content,
                                  nsIPresShell::ScrollAxis(),
                                  nsIPresShell::ScrollAxis(),
                                  nsIPresShell::SCROLL_FIRST_ANCESTOR_ONLY |
                                  nsIPresShell::SCROLL_OVERFLOW_HIDDEN);
     return NS_OK;
 }
 /* void ensureIndexIsVisible (in long index); */
 NS_IMETHODIMP nsScrollBoxObject::EnsureIndexIsVisible(int32_t index)
 {
     return NS_ERROR_NOT_IMPLEMENTED;
 }
 /* void ensureLineIsVisible (in long line); */
 NS_IMETHODIMP nsScrollBoxObject::EnsureLineIsVisible(int32_t line)
 {
     return NS_ERROR_NOT_IMPLEMENTED;
 }
 nsresult
 NS_NewScrollBoxObject(nsIBoxObject** aResult)
 {
   *aResult = new nsScrollBoxObject;
   if (!*aResult)
     return NS_ERROR_OUT_OF_MEMORY;
   NS_ADDREF(*aResult);
   return NS_OK;
 }

The Tor Browser / annotate

layout/xul/nsScrollBoxObject.cpp@925c144e1f1f (annotated)

layout/xul/nsScrollBoxObject.cpp