gecko-dev/layout/generic/nsViewportFrame.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
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*
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* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
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* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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/*
* rendering object that is the root of the frame tree, which contains
* the document's scrollbars and contains fixed-positioned elements
*/
#include "nsCOMPtr.h"
#include "nsViewportFrame.h"
#include "nsHTMLParts.h"
#include "nsLayoutAtoms.h"
#include "nsIViewManager.h"
#include "nsIScrollableFrame.h"
#include "nsIDeviceContext.h"
#include "nsPresContext.h"
#include "nsReflowPath.h"
#include "nsIPresShell.h"
nsIFrame*
NS_NewViewportFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) ViewportFrame(aContext);
}
NS_IMETHODIMP
ViewportFrame::Destroy(nsPresContext* aPresContext)
{
mFixedContainer.DestroyFrames(this, aPresContext);
return nsContainerFrame::Destroy(aPresContext);
}
NS_IMETHODIMP
ViewportFrame::SetInitialChildList(nsPresContext* aPresContext,
nsIAtom* aListName,
nsIFrame* aChildList)
{
nsresult rv = NS_OK;
// See which child list to add the frames to
#ifdef NS_DEBUG
nsFrame::VerifyDirtyBitSet(aChildList);
#endif
if (mFixedContainer.GetChildListName() == aListName) {
rv = mFixedContainer.SetInitialChildList(this, aPresContext, aListName, aChildList);
}
else {
rv = nsContainerFrame::SetInitialChildList(aPresContext, aListName, aChildList);
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
// We don't need any special painting or event handling. We just need to
// mark our visible out-of-flow frames (i.e., the fixed position frames) so
// that display list construction is guaranteed to recurse into their
// ancestors.
MarkOutOfFlowChildrenForDisplayList(mFixedContainer.GetFirstChild(), aDirtyRect);
nsIFrame* kid = mFrames.FirstChild();
nsresult rv = NS_OK;
if (kid) {
// make the kid's BorderBackground our own. This ensures that the canvas
// frame's background becomes our own background and therefore appears
// below negative z-index elements.
rv = BuildDisplayListForChild(aBuilder, kid, aDirtyRect, aLists);
}
UnmarkOutOfFlowChildrenForDisplayList(mFixedContainer.GetFirstChild());
return rv;
}
NS_IMETHODIMP
ViewportFrame::AppendFrames(nsIAtom* aListName,
nsIFrame* aFrameList)
{
nsresult rv = NS_OK;
if (mFixedContainer.GetChildListName() == aListName) {
rv = mFixedContainer.AppendFrames(this, aListName, aFrameList);
}
else {
// We only expect incremental changes for our fixed frames
NS_ERROR("unexpected child list");
rv = NS_ERROR_INVALID_ARG;
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::InsertFrames(nsIAtom* aListName,
nsIFrame* aPrevFrame,
nsIFrame* aFrameList)
{
nsresult rv = NS_OK;
if (mFixedContainer.GetChildListName() == aListName) {
rv = mFixedContainer.InsertFrames(this, aListName, aPrevFrame, aFrameList);
}
else {
// We only expect incremental changes for our fixed frames
NS_ERROR("unexpected child list");
rv = NS_ERROR_INVALID_ARG;
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::RemoveFrame(nsIAtom* aListName,
nsIFrame* aOldFrame)
{
nsresult rv = NS_OK;
if (mFixedContainer.GetChildListName() == aListName) {
rv = mFixedContainer.RemoveFrame(this, aListName, aOldFrame);
}
else {
// We only expect incremental changes for our fixed frames
NS_ERROR("unexpected child list");
rv = NS_ERROR_INVALID_ARG;
}
return rv;
}
nsIAtom*
ViewportFrame::GetAdditionalChildListName(PRInt32 aIndex) const
{
NS_PRECONDITION(aIndex >= 0, "illegal index");
if (0 == aIndex) {
return mFixedContainer.GetChildListName();
}
return nsnull;
}
nsIFrame*
ViewportFrame::GetFirstChild(nsIAtom* aListName) const
{
if (mFixedContainer.GetChildListName() == aListName) {
nsIFrame* result = nsnull;
mFixedContainer.FirstChild(this, aListName, &result);
return result;
}
return nsContainerFrame::GetFirstChild(aListName);
}
nsPoint
ViewportFrame::AdjustReflowStateForScrollbars(nsHTMLReflowState* aReflowState) const
{
// Calculate how much room is available for fixed frames. That means
// determining if the viewport is scrollable and whether the vertical and/or
// horizontal scrollbars are visible
// Get our prinicpal child frame and see if we're scrollable
nsIFrame* kidFrame = mFrames.FirstChild();
nsCOMPtr<nsIScrollableFrame> scrollingFrame(do_QueryInterface(kidFrame));
if (scrollingFrame) {
nsMargin scrollbars = scrollingFrame->GetActualScrollbarSizes();
aReflowState->mComputedWidth -= scrollbars.left + scrollbars.right;
aReflowState->availableWidth -= scrollbars.left + scrollbars.right;
aReflowState->mComputedHeight -= scrollbars.top + scrollbars.bottom;
// XXX why don't we also adjust "aReflowState->availableHeight"?
return nsPoint(scrollbars.left, scrollbars.top);
}
return nsPoint(0, 0);
}
NS_IMETHODIMP
ViewportFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
DO_GLOBAL_REFLOW_COUNT("ViewportFrame", aReflowState.reason);
DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
NS_FRAME_TRACE_REFLOW_IN("ViewportFrame::Reflow");
NS_PRECONDITION(!aDesiredSize.mComputeMEW, "unexpected request");
// Initialize OUT parameters
aStatus = NS_FRAME_COMPLETE;
// Reflow the main content first so that the placeholders of the
// fixed-position frames will be in the right places on an initial
// reflow.
nsRect kidRect(0,0,aReflowState.availableWidth,aReflowState.availableHeight);
nsresult rv = NS_OK;
if (mFrames.NotEmpty()) {
// Deal with a non-incremental reflow or an incremental reflow
// targeted at our one-and-only principal child frame.
if (eReflowReason_Incremental != aReflowState.reason ||
aReflowState.path->HasChild(mFrames.FirstChild())) {
// Reflow our one-and-only principal child frame
nsIFrame* kidFrame = mFrames.FirstChild();
nsHTMLReflowMetrics kidDesiredSize(nsnull);
nsSize availableSpace(aReflowState.availableWidth,
aReflowState.availableHeight);
nsHTMLReflowState kidReflowState(aPresContext, aReflowState,
kidFrame, availableSpace);
// Reflow the frame
kidReflowState.mComputedHeight = aReflowState.availableHeight;
rv = ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowState,
0, 0, 0, aStatus);
kidRect.width = kidDesiredSize.width;
kidRect.height = kidDesiredSize.height;
FinishReflowChild(kidFrame, aPresContext, nsnull, kidDesiredSize, 0, 0, 0);
}
}
// If we were flowed initially at both an unconstrained width and height,
// this is a hint that we should return our child's intrinsic size.
if ((eReflowReason_Initial == aReflowState.reason ||
eReflowReason_Resize == aReflowState.reason) &&
aReflowState.availableWidth == NS_UNCONSTRAINEDSIZE &&
aReflowState.availableHeight == NS_UNCONSTRAINEDSIZE) {
aDesiredSize.width = kidRect.width;
aDesiredSize.height = kidRect.height;
aDesiredSize.ascent = kidRect.height;
aDesiredSize.descent = 0;
}
else {
// Return the max size as our desired size
aDesiredSize.width = aReflowState.availableWidth;
aDesiredSize.height = aReflowState.availableHeight;
aDesiredSize.ascent = aReflowState.availableHeight;
aDesiredSize.descent = 0;
}
// Make a copy of the reflow state and change the computed width and height
// to reflect the available space for the fixed items
nsHTMLReflowState reflowState(aReflowState);
nsPoint offset = AdjustReflowStateForScrollbars(&reflowState);
#ifdef DEBUG
nsIFrame* f;
mFixedContainer.FirstChild(this, nsLayoutAtoms::fixedList, &f);
NS_ASSERTION(!f || (offset.x == 0 && offset.y == 0),
"We don't handle correct positioning of fixed frames with "
"scrollbars in odd positions");
#endif
nsReflowType reflowType = eReflowType_ContentChanged;
if (aReflowState.path) {
// XXXwaterson this is more restrictive than the previous code
// was: it insists that the UserDefined reflow be targeted at
// _this_ frame.
nsHTMLReflowCommand *command = aReflowState.path->mReflowCommand;
if (command)
command->GetType(reflowType);
}
if (reflowType != eReflowType_UserDefined &&
aReflowState.reason == eReflowReason_Incremental) {
// Incremental reflow
mFixedContainer.IncrementalReflow(this, aPresContext, reflowState,
reflowState.mComputedWidth,
reflowState.mComputedHeight);
}
// Just reflow all the fixed-pos frames.
rv = mFixedContainer.Reflow(this, aPresContext, reflowState,
reflowState.mComputedWidth,
reflowState.mComputedHeight);
// If this is an initial reflow, resize reflow, or style change reflow
// then do a repaint
if ((eReflowReason_Initial == aReflowState.reason) ||
(eReflowReason_Resize == aReflowState.reason) ||
(eReflowReason_StyleChange == aReflowState.reason)) {
nsRect damageRect(0, 0, aDesiredSize.width, aDesiredSize.height);
Invalidate(damageRect, PR_FALSE);
}
NS_FRAME_TRACE_REFLOW_OUT("ViewportFrame::Reflow", aStatus);
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return rv;
}
nsIAtom*
ViewportFrame::GetType() const
{
return nsLayoutAtoms::viewportFrame;
}
/* virtual */ PRBool
ViewportFrame::IsContainingBlock() const
{
return PR_TRUE;
}
#ifdef DEBUG
NS_IMETHODIMP
ViewportFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("Viewport"), aResult);
}
#endif