gecko-dev/layout/generic/nsViewportFrame.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License 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 Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#include "nsCOMPtr.h"
#include "nsContainerFrame.h"
#include "nsHTMLParts.h"
#include "nsHTMLIIDs.h"
#include "nsLayoutAtoms.h"
#include "nsIViewManager.h"
#include "nsIScrollableView.h"
#include "nsIDeviceContext.h"
#include "nsIPresContext.h"
#include "nsIReflowCommand.h"
#include "nsIPresShell.h"
static NS_DEFINE_IID(kIFrameIID, NS_IFRAME_IID);
static NS_DEFINE_IID(kScrollViewIID, NS_ISCROLLABLEVIEW_IID);
/**
* Viewport frame class.
*
* The viewport frame is the parent frame for the document element's frame.
* It only supports having a single child frame which must be one of the
* following:
* - scroll frame
* - root frame
*
* The viewport frame has an additional named child list:
* - "Fixed-list" which contains the fixed positioned frames
*
* @see nsLayoutAtoms::fixedList
*/
class ViewportFrame : public nsContainerFrame {
public:
NS_IMETHOD Destroy(nsIPresContext* aPresContext);
NS_IMETHOD SetInitialChildList(nsIPresContext* aPresContext,
nsIAtom* aListName,
nsIFrame* aChildList);
NS_IMETHOD GetFrameForPoint(nsIPresContext* aPresContext,
const nsPoint& aPoint,
nsFramePaintLayer aWhichLayer,
nsIFrame** aFrame);
NS_IMETHOD AppendFrames(nsIPresContext* aPresContext,
nsIPresShell& aPresShell,
nsIAtom* aListName,
nsIFrame* aFrameList);
NS_IMETHOD InsertFrames(nsIPresContext* aPresContext,
nsIPresShell& aPresShell,
nsIAtom* aListName,
nsIFrame* aPrevFrame,
nsIFrame* aFrameList);
NS_IMETHOD RemoveFrame(nsIPresContext* aPresContext,
nsIPresShell& aPresShell,
nsIAtom* aListName,
nsIFrame* aOldFrame);
NS_IMETHOD GetAdditionalChildListName(PRInt32 aIndex,
nsIAtom** aListName) const;
NS_IMETHOD FirstChild(nsIPresContext* aPresContext,
nsIAtom* aListName,
nsIFrame** aFirstChild) const;
NS_IMETHOD Reflow(nsIPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus);
/**
* Get the "type" of the frame
*
* @see nsLayoutAtoms::viewportFrame
*/
NS_IMETHOD GetFrameType(nsIAtom** aType) const;
#ifdef DEBUG
NS_IMETHOD GetFrameName(nsString& aResult) const;
NS_IMETHOD SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const;
#endif
protected:
nsresult IncrementalReflow(nsIPresContext* aPresContext,
const nsHTMLReflowState& aReflowState);
nsresult ReflowFixedFrame(nsIPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nsIFrame* aKidFrame,
PRBool aInitialReflow,
nsReflowStatus& aStatus) const;
void ReflowFixedFrames(nsIPresContext* aPresContext,
const nsHTMLReflowState& aReflowState) const;
void CalculateFixedContainingBlockSize(nsIPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nscoord& aWidth,
nscoord& aHeight) const;
private:
nsFrameList mFixedFrames; // additional named child list
};
//----------------------------------------------------------------------
nsresult
NS_NewViewportFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame)
{
NS_PRECONDITION(aNewFrame, "null OUT ptr");
if (nsnull == aNewFrame) {
return NS_ERROR_NULL_POINTER;
}
ViewportFrame* it = new (aPresShell) ViewportFrame;
if (nsnull == it) {
return NS_ERROR_OUT_OF_MEMORY;
}
*aNewFrame = it;
return NS_OK;
}
NS_IMETHODIMP
ViewportFrame::Destroy(nsIPresContext* aPresContext)
{
mFixedFrames.DestroyFrames(aPresContext);
return nsContainerFrame::Destroy(aPresContext);
}
NS_IMETHODIMP
ViewportFrame::SetInitialChildList(nsIPresContext* aPresContext,
nsIAtom* aListName,
nsIFrame* aChildList)
{
nsresult rv;
// See which child list to add the frames to
#ifdef NS_DEBUG
nsFrame::VerifyDirtyBitSet(aChildList);
#endif
if (nsLayoutAtoms::fixedList == aListName) {
mFixedFrames.SetFrames(aChildList);
rv = NS_OK;
} else {
rv = nsContainerFrame::SetInitialChildList(aPresContext, aListName, aChildList);
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::GetFrameForPoint(nsIPresContext* aPresContext,
const nsPoint& aPoint,
nsFramePaintLayer aWhichLayer,
nsIFrame** aFrame)
{
// this should act like a block, so we need to override
return GetFrameForPointUsing(aPresContext, aPoint, nsnull, aWhichLayer, (aWhichLayer == NS_FRAME_PAINT_LAYER_BACKGROUND), aFrame);
}
NS_IMETHODIMP
ViewportFrame::AppendFrames(nsIPresContext* aPresContext,
nsIPresShell& aPresShell,
nsIAtom* aListName,
nsIFrame* aFrameList)
{
nsresult rv;
NS_PRECONDITION(nsLayoutAtoms::fixedList == aListName, "unexpected child list");
if (aListName != nsLayoutAtoms::fixedList) {
// We only expect incremental changes for our fixed frames
rv = NS_ERROR_INVALID_ARG;
} else {
// Add the frames to our list of fixed position frames
#ifdef NS_DEBUG
nsFrame::VerifyDirtyBitSet(aFrameList);
#endif
mFixedFrames.AppendFrames(nsnull, aFrameList);
// Generate a reflow command to reflow the dirty frames
nsIReflowCommand* reflowCmd;
rv = NS_NewHTMLReflowCommand(&reflowCmd, this, nsIReflowCommand::ReflowDirty);
if (NS_SUCCEEDED(rv)) {
reflowCmd->SetChildListName(nsLayoutAtoms::fixedList);
aPresShell.AppendReflowCommand(reflowCmd);
NS_RELEASE(reflowCmd);
}
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::InsertFrames(nsIPresContext* aPresContext,
nsIPresShell& aPresShell,
nsIAtom* aListName,
nsIFrame* aPrevFrame,
nsIFrame* aFrameList)
{
nsresult rv;
NS_PRECONDITION(nsLayoutAtoms::fixedList == aListName, "unexpected child list");
if (aListName != nsLayoutAtoms::fixedList) {
// We only expect incremental changes for our fixed frames
rv = NS_ERROR_INVALID_ARG;
} else {
// Insert the new frames
#ifdef NS_DEBUG
nsFrame::VerifyDirtyBitSet(aFrameList);
#endif
mFixedFrames.InsertFrames(nsnull, aPrevFrame, aFrameList);
// Generate a reflow command to reflow the dirty frames
nsIReflowCommand* reflowCmd;
rv = NS_NewHTMLReflowCommand(&reflowCmd, this, nsIReflowCommand::ReflowDirty);
if (NS_SUCCEEDED(rv)) {
reflowCmd->SetChildListName(nsLayoutAtoms::fixedList);
aPresShell.AppendReflowCommand(reflowCmd);
NS_RELEASE(reflowCmd);
}
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::RemoveFrame(nsIPresContext* aPresContext,
nsIPresShell& aPresShell,
nsIAtom* aListName,
nsIFrame* aOldFrame)
{
nsresult rv;
NS_PRECONDITION(nsLayoutAtoms::fixedList == aListName, "unexpected child list");
if (aListName != nsLayoutAtoms::fixedList) {
// We only expect incremental changes for our fixed frames
rv = NS_ERROR_INVALID_ARG;
} else {
PRBool result = mFixedFrames.DestroyFrame(aPresContext, aOldFrame);
NS_ASSERTION(result, "didn't find frame to delete");
// Because fixed frames aren't part of a flow, there's no additional
// work to do, e.g. reflowing sibling frames. And because fixed frames
// have a view, we don't need to repaint
rv = result ? NS_OK : NS_ERROR_FAILURE;
}
return rv;
}
NS_IMETHODIMP
ViewportFrame::GetAdditionalChildListName(PRInt32 aIndex,
nsIAtom** aListName) const
{
NS_PRECONDITION(nsnull != aListName, "null OUT parameter pointer");
*aListName = nsnull;
if (aIndex < 0) {
return NS_ERROR_INVALID_ARG;
} else if (0 == aIndex) {
*aListName = nsLayoutAtoms::fixedList;
NS_ADDREF(*aListName);
}
return NS_OK;
}
NS_IMETHODIMP
ViewportFrame::FirstChild(nsIPresContext* aPresContext,
nsIAtom* aListName,
nsIFrame** aFirstChild) const
{
NS_PRECONDITION(nsnull != aFirstChild, "null OUT parameter pointer");
if (aListName == nsLayoutAtoms::fixedList) {
*aFirstChild = mFixedFrames.FirstChild();
return NS_OK;
}
return nsContainerFrame::FirstChild(aPresContext, aListName, aFirstChild);
}
void
ViewportFrame::CalculateFixedContainingBlockSize(nsIPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nscoord& aWidth,
nscoord& aHeight) const
{
// Initialize the values to the computed width/height in our reflow
// state struct
aWidth = aReflowState.mComputedWidth;
aHeight = aReflowState.mComputedHeight;
// Get our prinicpal child frame and see if we're scrollable
nsIFrame* kidFrame = mFrames.FirstChild();
nsIView* kidView;
kidFrame->GetView(aPresContext, &kidView);
if (nsnull != kidView) {
nsIScrollableView* scrollingView;
if (NS_SUCCEEDED(kidView->QueryInterface(kScrollViewIID, (void**)&scrollingView))) {
// Get the scrollbar dimensions
float sbWidth, sbHeight;
nsCOMPtr<nsIDeviceContext> dc;
aPresContext->GetDeviceContext(getter_AddRefs(dc));
dc->GetScrollBarDimensions(sbWidth, sbHeight);
// See if the scrollbars are visible
PRBool vertSBVisible, horzSBVisible;
scrollingView->GetScrollbarVisibility(&vertSBVisible, &horzSBVisible);
if (vertSBVisible) {
aWidth -= NSToCoordRound(sbWidth);
}
if (horzSBVisible) {
aHeight -= NSToCoordRound(sbHeight);
}
}
}
}
nsresult
ViewportFrame::ReflowFixedFrame(nsIPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nsIFrame* aKidFrame,
PRBool aInitialReflow,
nsReflowStatus& aStatus) const
{
// Reflow the frame
nsresult rv;
nsHTMLReflowMetrics kidDesiredSize(nsnull);
nsSize availSize(aReflowState.availableWidth, NS_UNCONSTRAINEDSIZE);
nsHTMLReflowState kidReflowState(aPresContext, aReflowState, aKidFrame,
availSize);
// If it's the initial reflow, then override the reflow reason. This is
// used when frames are inserted incrementally
if (aInitialReflow) {
kidReflowState.reason = eReflowReason_Initial;
}
// Send the WillReflow() notification and position the frame
aKidFrame->WillReflow(aPresContext);
aKidFrame->MoveTo(aPresContext,
kidReflowState.mComputedOffsets.left + kidReflowState.mComputedMargin.left,
kidReflowState.mComputedOffsets.top + kidReflowState.mComputedMargin.top);
// Position its view
nsIView* kidView;
aKidFrame->GetView(aPresContext, &kidView);
nsContainerFrame::PositionFrameView(aPresContext, aKidFrame, kidView);
// Do the reflow
rv = aKidFrame->Reflow(aPresContext, kidDesiredSize, kidReflowState, aStatus);
// XXX If the child had a fixed height, then make sure it respected it...
if (NS_AUTOHEIGHT != kidReflowState.mComputedHeight) {
if (kidDesiredSize.height < kidReflowState.mComputedHeight) {
kidDesiredSize.height = kidReflowState.mComputedHeight;
kidDesiredSize.height += kidReflowState.mComputedBorderPadding.top +
kidReflowState.mComputedBorderPadding.bottom;
}
}
// Position the child
nsRect rect(kidReflowState.mComputedOffsets.left + kidReflowState.mComputedMargin.left,
kidReflowState.mComputedOffsets.top + kidReflowState.mComputedMargin.top,
kidDesiredSize.width, kidDesiredSize.height);
aKidFrame->SetRect(aPresContext, rect);
// Size and position the view and set its opacity, visibility, content
// transparency, and clip
nsContainerFrame::SyncFrameViewAfterReflow(aPresContext, aKidFrame, kidView,
&kidDesiredSize.mOverflowArea);
aKidFrame->DidReflow(aPresContext, NS_FRAME_REFLOW_FINISHED);
return rv;
}
// Called by Reflow() to reflow all of the fixed positioned child frames.
// This is only done for 'initial', 'resize', and 'style change' reflow commands
void
ViewportFrame::ReflowFixedFrames(nsIPresContext* aPresContext,
const nsHTMLReflowState& aReflowState) const
{
NS_PRECONDITION(eReflowReason_Incremental != aReflowState.reason,
"unexpected reflow reason");
// Calculate how much room is available for the fixed items. That means
// determining if the viewport is scrollable and whether the vertical and/or
// horizontal scrollbars are visible
nscoord width, height;
CalculateFixedContainingBlockSize(aPresContext, aReflowState, width, height);
// Make a copy of the reflow state and change the computed width and height
// to reflect the available space for the fixed items
// XXX Find a cleaner way to do this...
nsHTMLReflowState reflowState(aReflowState);
reflowState.mComputedWidth = width;
reflowState.mComputedHeight = height;
nsIFrame* kidFrame;
for (kidFrame = mFixedFrames.FirstChild(); nsnull != kidFrame; kidFrame->GetNextSibling(&kidFrame)) {
// Reflow the frame using our reflow reason
nsReflowStatus kidStatus;
ReflowFixedFrame(aPresContext, reflowState, kidFrame, PR_FALSE, kidStatus);
}
}
/**
* Called by Reflow() to handle the case where it's an incremental reflow
* of a fixed child frame
*/
nsresult
ViewportFrame::IncrementalReflow(nsIPresContext* aPresContext,
const nsHTMLReflowState& aReflowState)
{
nsIReflowCommand::ReflowType type;
// Get the type of reflow command
aReflowState.reflowCommand->GetType(type);
// The only type of reflow command we expect is that we have dirty
// child frames to reflow
NS_ASSERTION(nsIReflowCommand::ReflowDirty, "unexpected reflow type");
// Calculate how much room is available for the fixed items. That means
// determining if the viewport is scrollable and whether the vertical and/or
// horizontal scrollbars are visible
nscoord width, height;
CalculateFixedContainingBlockSize(aPresContext, aReflowState, width, height);
// Make a copy of the reflow state and change the computed width and height
// to reflect the available space for the fixed items
// XXX Find a cleaner way to do this...
nsHTMLReflowState reflowState(aReflowState);
reflowState.mComputedWidth = width;
reflowState.mComputedHeight = height;
// Walk the fixed child frames and reflow the dirty frames
for (nsIFrame* f = mFixedFrames.FirstChild(); f; f->GetNextSibling(&f)) {
nsFrameState frameState;
f->GetFrameState(&frameState);
if (frameState & NS_FRAME_IS_DIRTY) {
nsReflowStatus status;
// Note: the only reason the frame would be dirty would be if it had
// just been inserted or appended
NS_ASSERTION(frameState & NS_FRAME_FIRST_REFLOW, "unexpected frame state");
ReflowFixedFrame(aPresContext, reflowState, f, PR_TRUE, status);
}
}
return NS_OK;
}
NS_IMETHODIMP
ViewportFrame::Reflow(nsIPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
DO_GLOBAL_REFLOW_COUNT("ViewportFrame", aReflowState.reason);
NS_FRAME_TRACE_REFLOW_IN("ViewportFrame::Reflow");
NS_PRECONDITION(nsnull == aDesiredSize.maxElementSize, "unexpected request");
// Initialize OUT parameter
aStatus = NS_FRAME_COMPLETE;
nsIFrame* nextFrame = nsnull;
PRBool isHandled = PR_FALSE;
// Check for an incremental reflow
if (eReflowReason_Incremental == aReflowState.reason) {
// See if we're the target frame
nsIFrame* targetFrame;
aReflowState.reflowCommand->GetTarget(targetFrame);
if (this == targetFrame) {
nsIAtom* listName;
PRBool isFixedChild;
// It's targeted at us. It better be for the fixed child list
aReflowState.reflowCommand->GetChildListName(listName);
isFixedChild = nsLayoutAtoms::fixedList == listName;
NS_IF_RELEASE(listName);
NS_ASSERTION(isFixedChild, "unexpected child list");
if (isFixedChild) {
// Handle the incremental reflow command
IncrementalReflow(aPresContext, aReflowState);
isHandled = PR_TRUE;
}
} else {
// Get the next frame in the reflow chain
aReflowState.reflowCommand->GetNext(nextFrame);
}
}
nsRect kidRect(0,0,aReflowState.availableWidth,aReflowState.availableHeight);
if (!isHandled) {
if ((eReflowReason_Incremental == aReflowState.reason) &&
(mFixedFrames.ContainsFrame(nextFrame))) {
// Reflow the 'fixed' frame that's the next frame in the reflow path
nsReflowStatus kidStatus;
ReflowFixedFrame(aPresContext, aReflowState, nextFrame, PR_FALSE,
kidStatus);
} else {
// Reflow our one and only principal child frame
if (mFrames.NotEmpty()) {
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;
ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowState,
0, 0, 0, aStatus);
kidRect.width = kidDesiredSize.width;
kidRect.height = kidDesiredSize.height;
FinishReflowChild(kidFrame, aPresContext, kidDesiredSize, 0, 0, 0);
}
// If it's a 'initial', 'resize', or 'style change' reflow command (anything
// but incremental), then reflow all the fixed positioned child frames
if (eReflowReason_Incremental != aReflowState.reason) {
ReflowFixedFrames(aPresContext, aReflowState);
}
}
}
// 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;
}
// 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(aPresContext, damageRect, PR_FALSE);
}
NS_FRAME_TRACE_REFLOW_OUT("ViewportFrame::Reflow", aStatus);
return NS_OK;
}
NS_IMETHODIMP
ViewportFrame::GetFrameType(nsIAtom** aType) const
{
NS_PRECONDITION(nsnull != aType, "null OUT parameter pointer");
*aType = nsLayoutAtoms::viewportFrame;
NS_ADDREF(*aType);
return NS_OK;
}
#ifdef DEBUG
NS_IMETHODIMP
ViewportFrame::GetFrameName(nsString& aResult) const
{
return MakeFrameName("Viewport", aResult);
}
NS_IMETHODIMP
ViewportFrame::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
{
if (!aResult) {
return NS_ERROR_NULL_POINTER;
}
*aResult = sizeof(*this);
return NS_OK;
}
#endif