gecko-dev/layout/xul/ScrollBoxObject.cpp

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C++

/* -*- 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 "mozilla/dom/ScrollBoxObject.h"
#include "mozilla/dom/ScrollBoxObjectBinding.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/ToJSValue.h"
#include "nsCOMPtr.h"
#include "nsIPresShell.h"
#include "nsIContent.h"
#include "nsIDOMElement.h"
#include "nsPresContext.h"
#include "nsBox.h"
#include "nsIScrollableFrame.h"
namespace mozilla {
namespace dom {
ScrollBoxObject::ScrollBoxObject()
{
}
ScrollBoxObject::~ScrollBoxObject()
{
}
JSObject* ScrollBoxObject::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
return ScrollBoxObjectBinding::Wrap(aCx, this, aGivenProto);
}
nsIScrollableFrame* ScrollBoxObject::GetScrollFrame()
{
return do_QueryFrame(GetFrame(false));
}
void ScrollBoxObject::ScrollTo(int32_t x, int32_t y, ErrorResult& aRv)
{
nsIScrollableFrame* sf = GetScrollFrame();
if (!sf) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
sf->ScrollToCSSPixels(CSSIntPoint(x, y));
}
void ScrollBoxObject::ScrollBy(int32_t dx, int32_t dy, ErrorResult& aRv)
{
CSSIntPoint pt;
GetPosition(pt, aRv);
if (aRv.Failed()) {
return;
}
ScrollTo(pt.x + dx, pt.y + dy, aRv);
}
void ScrollBoxObject::ScrollByLine(int32_t dlines, ErrorResult& aRv)
{
nsIScrollableFrame* sf = GetScrollFrame();
if (!sf) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
sf->ScrollBy(nsIntPoint(0, dlines), nsIScrollableFrame::LINES,
nsIScrollableFrame::SMOOTH);
}
// 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(BoxObject* aScrollBox) {
nsIFrame* frame = aScrollBox->GetFrame(false);
if (!frame) {
return nullptr;
}
nsIScrollableFrame* scrollFrame = do_QueryFrame(frame);
if (!scrollFrame) {
NS_WARNING("ScrollBoxObject attached to something that's not a scroll frame!");
return nullptr;
}
nsIFrame* scrolledFrame = scrollFrame->GetScrolledFrame();
if (!scrolledFrame)
return nullptr;
return nsBox::GetChildXULBox(scrolledFrame);
}
void ScrollBoxObject::ScrollByIndex(int32_t dindexes, ErrorResult& aRv)
{
nsIScrollableFrame* sf = GetScrollFrame();
if (!sf) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
nsIFrame* scrolledBox = GetScrolledBox(this);
if (!scrolledBox) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
nsRect rect;
// now get the scrolled boxes first child.
nsIFrame* child = nsBox::GetChildXULBox(scrolledBox);
bool horiz = scrolledBox->IsXULHorizontal();
nsPoint cp = sf->GetScrollPosition();
nscoord diff = 0;
int32_t curIndex = 0;
bool isLTR = scrolledBox->IsXULNormalDirection();
int32_t frameWidth = 0;
if (!isLTR && horiz) {
GetWidth(&frameWidth);
nsCOMPtr<nsIPresShell> shell = GetPresShell(false);
if (!shell) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return;
}
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::GetNextXULBox(child);
curIndex++;
}
int32_t count = 0;
if (dindexes == 0)
return;
if (dindexes > 0) {
while(child) {
child = nsBox::GetNextXULBox(child);
if (child) {
rect = child->GetRect();
}
count++;
if (count >= dindexes) {
break;
}
}
} else if (dindexes < 0) {
child = nsBox::GetChildXULBox(scrolledBox);
while(child) {
rect = child->GetRect();
if (count >= curIndex + dindexes) {
break;
}
count++;
child = nsBox::GetNextXULBox(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);
}
}
void ScrollBoxObject::ScrollToLine(int32_t line, ErrorResult& aRv)
{
nsIScrollableFrame* sf = GetScrollFrame();
if (!sf) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
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);
}
void ScrollBoxObject::ScrollToElement(Element& child, ErrorResult& aRv)
{
nsCOMPtr<nsIPresShell> shell = GetPresShell(false);
if (!shell) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return;
}
shell->ScrollContentIntoView(&child,
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);
}
void ScrollBoxObject::ScrollToIndex(int32_t index, ErrorResult& aRv)
{
aRv.Throw(NS_ERROR_NOT_IMPLEMENTED);
}
int32_t ScrollBoxObject::GetPositionX(ErrorResult& aRv)
{
CSSIntPoint pt;
GetPosition(pt, aRv);
return pt.x;
}
int32_t ScrollBoxObject::GetPositionY(ErrorResult& aRv)
{
CSSIntPoint pt;
GetPosition(pt, aRv);
return pt.y;
}
int32_t ScrollBoxObject::GetScrolledWidth(ErrorResult& aRv)
{
nsRect scrollRect;
GetScrolledSize(scrollRect, aRv);
return scrollRect.width;
}
int32_t ScrollBoxObject::GetScrolledHeight(ErrorResult& aRv)
{
nsRect scrollRect;
GetScrolledSize(scrollRect, aRv);
return scrollRect.height;
}
/* private helper */
void ScrollBoxObject::GetPosition(CSSIntPoint& aPos, ErrorResult& aRv)
{
nsIScrollableFrame* sf = GetScrollFrame();
if (!sf) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
aPos = sf->GetScrollPositionCSSPixels();
}
/* private helper */
void ScrollBoxObject::GetScrolledSize(nsRect& aRect, ErrorResult& aRv)
{
nsIFrame* scrolledBox = GetScrolledBox(this);
if (!scrolledBox) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
aRect = scrolledBox->GetRect();
aRect.width = nsPresContext::AppUnitsToIntCSSPixels(aRect.width);
aRect.height = nsPresContext::AppUnitsToIntCSSPixels(aRect.height);
}
void ScrollBoxObject::GetPosition(JSContext* cx,
JS::Handle<JSObject*> x,
JS::Handle<JSObject*> y,
ErrorResult& aRv)
{
CSSIntPoint pt;
GetPosition(pt, aRv);
JS::Rooted<JS::Value> v(cx);
if (!ToJSValue(cx, pt.x, &v) ||
!JS_SetProperty(cx, x, "value", v)) {
aRv.Throw(NS_ERROR_XPC_CANT_SET_OUT_VAL);
return;
}
if (!ToJSValue(cx, pt.y, &v) ||
!JS_SetProperty(cx, y, "value", v)) {
aRv.Throw(NS_ERROR_XPC_CANT_SET_OUT_VAL);
return;
}
}
void ScrollBoxObject::GetScrolledSize(JSContext* cx,
JS::Handle<JSObject*> width,
JS::Handle<JSObject*> height,
ErrorResult& aRv)
{
nsRect rect;
GetScrolledSize(rect, aRv);
JS::Rooted<JS::Value> v(cx);
if (!ToJSValue(cx, rect.width, &v) ||
!JS_SetProperty(cx, width, "value", v)) {
aRv.Throw(NS_ERROR_XPC_CANT_SET_OUT_VAL);
return;
}
if (!ToJSValue(cx, rect.height, &v) ||
!JS_SetProperty(cx, height, "value", v)) {
aRv.Throw(NS_ERROR_XPC_CANT_SET_OUT_VAL);
return;
}
}
void ScrollBoxObject::EnsureElementIsVisible(Element& child, ErrorResult& aRv)
{
nsCOMPtr<nsIPresShell> shell = GetPresShell(false);
if (!shell) {
aRv.Throw(NS_ERROR_UNEXPECTED);
return;
}
shell->ScrollContentIntoView(&child,
nsIPresShell::ScrollAxis(),
nsIPresShell::ScrollAxis(),
nsIPresShell::SCROLL_FIRST_ANCESTOR_ONLY |
nsIPresShell::SCROLL_OVERFLOW_HIDDEN);
}
void ScrollBoxObject::EnsureIndexIsVisible(int32_t index, ErrorResult& aRv)
{
aRv.Throw(NS_ERROR_NOT_IMPLEMENTED);
}
void ScrollBoxObject::EnsureLineIsVisible(int32_t line, ErrorResult& aRv)
{
aRv.Throw(NS_ERROR_NOT_IMPLEMENTED);
}
} // namespace dom
} // namespace mozilla
// Creation Routine ///////////////////////////////////////////////////////////////////////
using namespace mozilla::dom;
nsresult
NS_NewScrollBoxObject(nsIBoxObject** aResult)
{
NS_ADDREF(*aResult = new ScrollBoxObject());
return NS_OK;
}