gecko-dev/layout/xul/nsScrollBoxObject.cpp

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/* -*- 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 "nsBox.h"
#include "nsIScrollableFrame.h"
using namespace mozilla;
class nsScrollBoxObject MOZ_FINAL : public nsIScrollBoxObject,
public nsBoxObject
{
public:
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_NSISCROLLBOXOBJECT
nsScrollBoxObject();
virtual nsIScrollableFrame* GetScrollFrame() {
return do_QueryFrame(GetFrame(false));
}
protected:
virtual ~nsScrollBoxObject();
};
/* 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 nsBox::GetChildBox(scrolledFrame);
}
/* 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 = nsBox::GetChildBox(scrolledBox);
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 = nsBox::GetNextBox(child);
curIndex++;
}
int32_t count = 0;
if (dindexes == 0)
return NS_OK;
if (dindexes > 0) {
while(child) {
child = nsBox::GetNextBox(child);
if (child)
rect = child->GetRect();
count++;
if (count >= dindexes)
break;
}
} else if (dindexes < 0) {
child = nsBox::GetChildBox(scrolledBox);
while(child) {
rect = child->GetRect();
if (count >= curIndex + dindexes)
break;
count++;
child = nsBox::GetNextBox(child);
}
}
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),
0, 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;
}