gecko-dev/layout/generic/nsSpaceManager.cpp
1999-04-27 22:07:43 +00:00

1158 lines
34 KiB
C++

/* -*- 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 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#include "nsSpaceManager.h"
#include "nsPoint.h"
#include "nsRect.h"
#include "nsSize.h"
#include <stdlib.h>
#include "nsVoidArray.h"
static NS_DEFINE_IID(kISpaceManagerIID, NS_ISPACEMANAGER_IID);
PR_CALLBACK PLHashNumber
NS_HashNumber(const void* key)
{
return (PLHashNumber)key;
}
PR_CALLBACK PRIntn
NS_RemoveFrameInfoEntries(PLHashEntry* he, PRIntn i, void* arg)
{
nsSpaceManager::FrameInfo* frameInfo = (nsSpaceManager::FrameInfo*)he->value;
NS_ASSERTION(nsnull != frameInfo, "null frameInfo");
delete frameInfo;
return HT_ENUMERATE_REMOVE;
}
/////////////////////////////////////////////////////////////////////////////
// BandList
nsSpaceManager::BandList::BandList()
: nsSpaceManager::BandRect(-1, -1, -1, -1, (nsIFrame*)nsnull)
{
PR_INIT_CLIST(this);
numFrames = 0;
}
void
nsSpaceManager::BandList::Clear()
{
if (!IsEmpty()) {
BandRect* bandRect = Head();
while (bandRect != this) {
BandRect* next = bandRect->Next();
delete bandRect;
bandRect = next;
}
PR_INIT_CLIST(this);
}
}
/////////////////////////////////////////////////////////////////////////////
// nsSpaceManager
nsSpaceManager::nsSpaceManager(nsIFrame* aFrame)
: mFrame(aFrame)
{
NS_INIT_REFCNT();
mX = mY = 0;
mFrameInfoMap = nsnull;
}
void
nsSpaceManager::ClearFrameInfo()
{
if (nsnull != mFrameInfoMap) {
PL_HashTableEnumerateEntries(mFrameInfoMap, NS_RemoveFrameInfoEntries, 0);
PL_HashTableDestroy(mFrameInfoMap);
mFrameInfoMap = nsnull;
}
}
nsSpaceManager::~nsSpaceManager()
{
mBandList.Clear();
ClearFrameInfo();
}
NS_IMPL_ISUPPORTS(nsSpaceManager, kISpaceManagerIID);
NS_IMETHODIMP
nsSpaceManager::GetFrame(nsIFrame*& aFrame) const
{
aFrame = mFrame;
return NS_OK;
}
NS_IMETHODIMP
nsSpaceManager::Translate(nscoord aDx, nscoord aDy)
{
mX += aDx;
mY += aDy;
return NS_OK;
}
NS_IMETHODIMP
nsSpaceManager::GetTranslation(nscoord& aX, nscoord& aY) const
{
aX = mX;
aY = mY;
return NS_OK;
}
NS_IMETHODIMP
nsSpaceManager::YMost(nscoord& aYMost) const
{
if (mBandList.IsEmpty()) {
aYMost = 0;
} else {
BandRect* lastRect = mBandList.Tail();
aYMost = lastRect->bottom;
}
return NS_OK;
}
/**
* Internal function that returns the list of available and unavailable space
* within the band
*
* @param aBand the first rect in the band
* @param aY the y-offset in world coordinates
* @param aMaxSize the size to use to constrain the band data
* @param aAvailableBand
*/
nsresult
nsSpaceManager::GetBandAvailableSpace(const BandRect* aBand,
nscoord aY,
const nsSize& aMaxSize,
nsBandData& aBandData) const
{
nscoord topOfBand = aBand->top;
nscoord localY = aY - mY;
nscoord height = PR_MIN(aBand->bottom - aY, aMaxSize.height);
nsBandTrapezoid* trapezoid = aBandData.trapezoids;
nscoord rightEdge = mX + aMaxSize.width;
// Initialize the band data
aBandData.count = 0;
// Skip any rectangles that are to the left of the local coordinate space
while (aBand->top == topOfBand) {
if (aBand->right > mX) {
break;
}
// Get the next rect in the band
aBand = aBand->Next();
}
// This is used to track the current x-location within the band. This is in
// world coordinates
nscoord left = mX;
// Process the remaining rectangles that are within the clip width
while ((aBand->top == topOfBand) && (aBand->left < rightEdge)) {
// Compare the left edge of the occupied space with the current left
// coordinate
if (aBand->left > left) {
// The rect is to the right of our current left coordinate, so we've
// found some available space
if (aBandData.count >= aBandData.size) {
// Not enough space in the array of trapezoids
aBandData.count += 2 * aBand->Length() + 2; // estimate the number needed
return NS_ERROR_FAILURE;
}
trapezoid->state = nsBandTrapezoid::Available;
trapezoid->frame = nsnull;
// Assign the trapezoid a rectangular shape. The trapezoid must be in the
// local coordinate space, so convert the current left coordinate
*trapezoid = nsRect(left - mX, localY, aBand->left - left, height);
// Move to the next output rect
trapezoid++;
aBandData.count++;
}
// The rect represents unavailable space, so add another trapezoid
if (aBandData.count >= aBandData.size) {
// Not enough space in the array of trapezoids
aBandData.count += 2 * aBand->Length() + 1; // estimate the number needed
return NS_ERROR_FAILURE;
}
if (1 == aBand->numFrames) {
trapezoid->state = nsBandTrapezoid::Occupied;
trapezoid->frame = aBand->frame;
} else {
NS_ASSERTION(aBand->numFrames > 1, "unexpected frame count");
trapezoid->state = nsBandTrapezoid::OccupiedMultiple;
trapezoid->frames = aBand->frames;
}
nscoord x = aBand->left;
// The first band can straddle the clip rect
if (x < mX) {
// Clip the left edge
x = mX;
}
// Assign the trapezoid a rectangular shape. The trapezoid must be in the
// local coordinate space, so convert the rects's left coordinate
*trapezoid = nsRect(x - mX, localY, aBand->right - x, height);
// Move to the next output rect
trapezoid++;
aBandData.count++;
// Adjust our current x-location within the band
left = aBand->right;
// Move to the next rect within the band
aBand = aBand->Next();
}
// No more rects left in the band. If we haven't yet reached the right edge,
// then all the remaining space is available
if (left < rightEdge) {
if (aBandData.count >= aBandData.size) {
// Not enough space in the array of trapezoids
aBandData.count++;
return NS_ERROR_FAILURE;
}
trapezoid->state = nsBandTrapezoid::Available;
trapezoid->frame = nsnull;
// Assign the trapezoid a rectangular shape. The trapezoid must be in the
// local coordinate space, so convert the current left coordinate
*trapezoid = nsRect(left - mX, localY, rightEdge - left, height);
aBandData.count++;
}
return NS_OK;
}
NS_IMETHODIMP
nsSpaceManager::GetBandData(nscoord aYOffset,
const nsSize& aMaxSize,
nsBandData& aBandData) const
{
NS_PRECONDITION(aBandData.size >= 1, "bad band data");
nsresult result = NS_OK;
// Convert the y-offset to world coordinates
nscoord y = mY + aYOffset;
// If there are no unavailable rects or the offset is below the bottommost
// band, then all the space is available
nscoord yMost;
YMost(yMost);
if (y >= yMost) {
// All the requested space is available
aBandData.count = 1;
aBandData.trapezoids[0] = nsRect(0, aYOffset, aMaxSize.width, aMaxSize.height);
aBandData.trapezoids[0].state = nsBandTrapezoid::Available;
aBandData.trapezoids[0].frame = nsnull;
} else {
// Find the first band that contains the y-offset or is below the y-offset
NS_ASSERTION(!mBandList.IsEmpty(), "no bands");
BandRect* band = mBandList.Head();
aBandData.count = 0;
while (nsnull != band) {
if (band->top > y) {
// The band is below the y-offset. The area between the y-offset and
// the top of the band is available
aBandData.count = 1;
aBandData.trapezoids[0] =
nsRect(0, aYOffset, aMaxSize.width, PR_MIN(band->top - y, aMaxSize.height));
aBandData.trapezoids[0].state = nsBandTrapezoid::Available;
aBandData.trapezoids[0].frame = nsnull;
break;
} else if (y < band->bottom) {
// The band contains the y-offset. Return a list of available and
// unavailable rects within the band
return GetBandAvailableSpace(band, y, aMaxSize, aBandData);
} else {
// Skip to the next band
band = GetNextBand(band);
}
}
}
NS_POSTCONDITION(aBandData.count > 0, "unexpected band data count");
return result;
}
/**
* Skips to the start of the next band.
*
* @param aBandRect A rect within the band
* @returns The start of the next band, or nsnull of this is the last band.
*/
nsSpaceManager::BandRect*
nsSpaceManager::GetNextBand(const BandRect* aBandRect) const
{
nscoord topOfBand = aBandRect->top;
aBandRect = aBandRect->Next();
while (aBandRect != &mBandList) {
// Check whether this rect is part of the same band
if (aBandRect->top != topOfBand) {
// We found the start of the next band
return (BandRect*)aBandRect;
}
aBandRect = aBandRect->Next();
}
// No bands left
return nsnull;
}
/**
* Divides the current band into two vertically
*
* @param aBandRect the first rect in the band
* @param aBottom where to split the band. This becomes the bottom of the top
* part
*/
void
nsSpaceManager::DivideBand(BandRect* aBandRect, nscoord aBottom)
{
NS_PRECONDITION(aBottom < aBandRect->bottom, "bad height");
nscoord topOfBand = aBandRect->top;
BandRect* nextBand = GetNextBand(aBandRect);
if (nsnull == nextBand) {
nextBand = (BandRect*)&mBandList;
}
while (topOfBand == aBandRect->top) {
// Split the band rect into two vertically
BandRect* bottomBandRect = aBandRect->SplitVertically(aBottom);
// Insert the new bottom part
nextBand->InsertBefore(bottomBandRect);
// Move to the next rect in the band
aBandRect = aBandRect->Next();
}
}
PRBool
nsSpaceManager::CanJoinBands(BandRect* aBand, BandRect* aPrevBand)
{
PRBool result;
nscoord topOfBand = aBand->top;
nscoord topOfPrevBand = aPrevBand->top;
// The bands can be joined if:
// - they're adjacent
// - they have the same number of rects
// - each rect has the same left and right edge as its corresponding rect, and
// the rects are occupied by the same frames
if (aPrevBand->bottom == aBand->top) {
// Compare each of the rects in the two bands
while (PR_TRUE) {
if ((aBand->left != aPrevBand->left) || (aBand->right != aPrevBand->right)) {
// The rects have different edges
result = PR_FALSE;
break;
}
if (!aBand->HasSameFrameList(aPrevBand)) {
// The rects are occupied by different frames
result = PR_FALSE;
break;
}
// Move to the next rects within the bands
aBand = aBand->Next();
aPrevBand = aPrevBand->Next();
// Have we reached the end of either band?
PRBool endOfBand = aBand->top != topOfBand;
PRBool endOfPrevBand = aPrevBand->top != topOfPrevBand;
if (endOfBand || endOfPrevBand) {
result = endOfBand & endOfPrevBand;
break; // all done
}
}
} else {
// The bands aren't adjacent
result = PR_FALSE;
}
return result;
}
/**
* Tries to join the two adjacent bands. Returns PR_TRUE if successful and
* PR_FALSE otherwise
*
* If the two bands are joined, the previous band is the the band that's deleted
*/
PRBool
nsSpaceManager::JoinBands(BandRect* aBand, BandRect* aPrevBand)
{
if (CanJoinBands(aBand, aPrevBand)) {
BandRect* startOfNextBand = aBand;
while (aPrevBand != startOfNextBand) {
// Adjust the top of the band we're keeping, and then move to the next
// rect within the band
aBand->top = aPrevBand->top;
aBand = aBand->Next();
// Delete the rect from the previous band
BandRect* next = aPrevBand->Next();
aPrevBand->Remove();
delete aPrevBand;
aPrevBand = next;
}
return PR_TRUE;
}
return PR_FALSE;
}
/**
* Adds a new rect to a band.
*
* @param aBand the first rect in the band
* @param aBandRect the band rect to add to the band
*/
void
nsSpaceManager::AddRectToBand(BandRect* aBand, BandRect* aBandRect)
{
NS_PRECONDITION((aBand->top == aBandRect->top) &&
(aBand->bottom == aBandRect->bottom), "bad band");
NS_PRECONDITION(1 == aBandRect->numFrames, "shared band rect");
nscoord topOfBand = aBand->top;
// Figure out where in the band horizontally to insert the rect
do {
// Compare the left edge of the new rect with the left edge of the existing
// rect
if (aBandRect->left < aBand->left) {
// The new rect's left edge is to the left of the existing rect's left edge.
// Could be any of these cases (N is new rect, E is existing rect):
//
// Case 1: left-of Case 2: overlaps Case 3: N.contains(E)
// --------------- ---------------- ---------------------
// +-----+ +-----+ +-----+ +---------+
// | N | | E | | N | | N |
// +-----+ +-----+ +-----+ +---------+
// +-----+ +---+
// | E | | E |
// +-----+ +---+
//
// Do the two rectangles overlap?
if (aBandRect->right <= aBand->left) {
// No, the new rect is completely to the left of the existing rect
// (case #1). Insert a new rect
aBand->InsertBefore(aBandRect);
return;
}
// Yes, they overlap. Compare the right edges.
if (aBandRect->right > aBand->right) {
// The new rect's right edge is to the right of the existing rect's
// right edge (case #3). Split the new rect
BandRect* r1 = aBandRect->SplitHorizontally(aBand->left);
// Insert the part of the new rect that's to the left of the existing
// rect as a new band rect
aBand->InsertBefore(aBandRect);
// Continue below with the part that overlaps the existing rect
aBandRect = r1;
} else {
if (aBand->right > aBandRect->right) {
// The existing rect extends past the new rect (case #2). Split the
// existing rect
BandRect* r1 = aBand->SplitHorizontally(aBandRect->right);
// Insert the new right half of the existing rect
aBand->InsertAfter(r1);
}
// Insert the part of the new rect that's to the left of the existing
// rect
aBandRect->right = aBand->left;
aBand->InsertBefore(aBandRect);
// Mark the existing rect as shared
aBand->AddFrame(aBandRect->frame);
return;
}
}
if (aBandRect->left > aBand->left) {
// The new rect's left edge is to the right of the existing rect's left
// edge. Could be any one of these cases:
//
// Case 4: right-of Case 5: overlaps Case 6: E.Contains(N)
// --------------- ---------------- ---------------------
// +-----+ +-----+ +-----+ +------------+
// | E | | N | | E | | E |
// +-----+ +-----+ +-----+ +------------+
// +-----+ +-----+
// | N | | N |
// +-----+ +-----+
//
if (aBandRect->left >= aBand->right) {
// The new rect is to the right of the existing rect (case #4), so move
// to the next rect in the band
aBand = aBand->Next();
continue;
}
// The rects overlap, so divide the existing rect into two rects: the
// part to the left of the new rect, and the part that overlaps
BandRect* r1 = aBand->SplitHorizontally(aBandRect->left);
// Insert the new right half of the existing rect, and make it the current
// rect
aBand->InsertAfter(r1);
aBand = r1;
}
// At this point the left edge of the new rect is the same as the left edge
// of the existing rect
NS_ASSERTION(aBandRect->left == aBand->left, "unexpected rect");
// Compare which rect is wider, the new rect or the existing rect
if (aBand->right > aBandRect->right) {
// The existing rect is wider (case #6). Divide the existing rect into
// two rects: the part that overlaps, and the part to the right of the
// new rect
BandRect* r1 = aBand->SplitHorizontally(aBandRect->right);
// Insert the new right half of the existing rect
aBand->InsertAfter(r1);
// Mark the overlap as being shared
aBand->AddFrame(aBandRect->frame);
return;
} else {
// Indicate the frames share the existing rect
aBand->AddFrame(aBandRect->frame);
if (aBand->right == aBandRect->right) {
// The new and existing rect have the same right edge. We're all done,
// and the new band rect is no longer needed
delete aBandRect;
return;
} else {
// The new rect is wider than the existing rect (cases #5). Set the
// new rect to be the overhang, and move to the next rect within the band
aBandRect->left = aBand->right;
aBand = aBand->Next();
continue;
}
}
} while (aBand->top == topOfBand);
// Insert a new rect
aBand->InsertBefore(aBandRect);
}
// When comparing a rect to a band there are seven cases to consider.
// 'R' is the rect and 'B' is the band.
//
// Case 1 Case 2 Case 3 Case 4
// ------ ------ ------ ------
// +-----+ +-----+ +-----+ +-----+
// | R | | R | +-----+ +-----+ | | | |
// +-----+ +-----+ | | | R | | B | | B |
// +-----+ | B | +-----+ | | +-----+ | |
// | | | | +-----+ | R | +-----+
// | B | +-----+ +-----+
// | |
// +-----+
//
//
//
// Case 5 Case 6 Case 7
// ------ ------ ------
// +-----+ +-----+ +-----+ +-----+
// | | | R | | B | | | +-----+
// | B | +-----+ +-----+ | R | | B |
// | | | | +-----+
// +-----+ +-----+
// +-----+
// | R |
// +-----+
//
void
nsSpaceManager::InsertBandRect(BandRect* aBandRect)
{
// If there are no existing bands or this rect is below the bottommost
// band, then add a new band
nscoord yMost;
YMost(yMost);
if (aBandRect->top >= yMost) {
mBandList.Append(aBandRect);
return;
}
// Examine each band looking for a band that intersects this rect
NS_ASSERTION(!mBandList.IsEmpty(), "no bands");
BandRect* band = mBandList.Head();
while (nsnull != band) {
// Compare the top edge of this rect with the top edge of the band
if (aBandRect->top < band->top) {
// The top edge of the rect is above the top edge of the band.
// Is there any overlap?
if (aBandRect->bottom <= band->top) {
// Case #1. This rect is completely above the band, so insert a
// new band before the current band
band->InsertBefore(aBandRect);
break; // we're all done
}
// Case #2 and case #7. Divide this rect, creating a new rect for
// the part that's above the band
BandRect* bandRect1 = new BandRect(aBandRect->left, aBandRect->top,
aBandRect->right, band->top,
aBandRect->frame);
// Insert bandRect1 as a new band
band->InsertBefore(bandRect1);
// Modify this rect to exclude the part above the band
aBandRect->top = band->top;
} else if (aBandRect->top > band->top) {
// The top edge of the rect is below the top edge of the band. Is there
// any overlap?
if (aBandRect->top >= band->bottom) {
// Case #5. This rect is below the current band. Skip to the next band
band = GetNextBand(band);
continue;
}
// Case #3 and case #4. Divide the current band into two bands with the
// top band being the part that's above the rect
DivideBand(band, aBandRect->top);
// Skip to the bottom band that we just created
band = GetNextBand(band);
}
// At this point the rect and the band should have the same y-offset
NS_ASSERTION(aBandRect->top == band->top, "unexpected band");
// Is the band higher than the rect?
if (band->bottom > aBandRect->bottom) {
// Divide the band into two bands with the top band the same height
// as the rect
DivideBand(band, aBandRect->bottom);
}
if (aBandRect->bottom == band->bottom) {
// Add the rect to the band
AddRectToBand(band, aBandRect);
break;
} else {
// Case #4 and case #7. The rect contains the band vertically. Divide
// the rect, creating a new rect for the part that overlaps the band
BandRect* bandRect1 = new BandRect(aBandRect->left, aBandRect->top,
aBandRect->right, band->bottom,
aBandRect->frame);
// Add bandRect1 to the band
AddRectToBand(band, bandRect1);
// Modify aBandRect to be the part below the band
aBandRect->top = band->bottom;
// Continue with the next band
band = GetNextBand(band);
if (nsnull == band) {
// Append a new bottommost band
mBandList.Append(aBandRect);
break;
}
}
}
}
NS_IMETHODIMP
nsSpaceManager::AddRectRegion(nsIFrame* aFrame, const nsRect& aUnavailableSpace)
{
NS_PRECONDITION(nsnull != aFrame, "null frame");
// See if there is already a region associated with aFrame
FrameInfo* frameInfo = GetFrameInfoFor(aFrame);
if (nsnull != frameInfo) {
NS_WARNING("aFrame is already associated with a region");
return NS_ERROR_FAILURE;
}
// Convert the frame to world coordinates
nsRect rect(aUnavailableSpace.x + mX, aUnavailableSpace.y + mY,
aUnavailableSpace.width, aUnavailableSpace.height);
// Verify that the offset is within the defined coordinate space
if ((rect.x < 0) || (rect.y < 0)) {
NS_WARNING("invalid offset for rect region");
return NS_ERROR_INVALID_ARG;
}
// Create a frame info structure
frameInfo = CreateFrameInfo(aFrame, rect);
if (nsnull == frameInfo) {
return NS_ERROR_OUT_OF_MEMORY;
}
// Is the rect empty?
if (aUnavailableSpace.IsEmpty()) {
// The rect doesn't consume any space, so don't add any band data
return NS_OK;
}
// Allocate a band rect
BandRect* bandRect = new BandRect(rect.x, rect.y, rect.XMost(), rect.YMost(), aFrame);
if (nsnull == bandRect) {
return NS_ERROR_OUT_OF_MEMORY;
}
// Insert the band rect
InsertBandRect(bandRect);
return NS_OK;
}
NS_IMETHODIMP
nsSpaceManager::ResizeRectRegion(nsIFrame* aFrame,
nscoord aDeltaWidth,
nscoord aDeltaHeight,
AffectedEdge aEdge)
{
// Get the frame info associated with with aFrame
FrameInfo* frameInfo = GetFrameInfoFor(aFrame);
if (nsnull == frameInfo) {
NS_WARNING("no region associated with aFrame");
return NS_ERROR_INVALID_ARG;
}
// Compute new rect
nsRect rect(frameInfo->rect);
rect.SizeBy(aDeltaWidth, aDeltaHeight);
if (aEdge == LeftEdge) {
rect.x += aDeltaWidth;
}
// Verify that the offset is within the defined coordinate space
if ((rect.x < 0) || (rect.y < 0)) {
NS_WARNING("invalid offset when resizing rect region");
return NS_ERROR_FAILURE;
}
// For the time being just remove it and add it back in. Because
// AddRectRegion() operates relative to the local coordinate space,
// translate from world coordinates to the local coordinate space
rect.MoveBy(-mX, -mY);
RemoveRegion(aFrame);
return AddRectRegion(aFrame, rect);
}
NS_IMETHODIMP
nsSpaceManager::OffsetRegion(nsIFrame* aFrame, nscoord aDx, nscoord aDy)
{
// Get the frame info associated with with aFrame
FrameInfo* frameInfo = GetFrameInfoFor(aFrame);
if (nsnull == frameInfo) {
NS_WARNING("no region associated with aFrame");
return NS_ERROR_INVALID_ARG;
}
// Compute new rect
nsRect rect(frameInfo->rect);
rect.MoveBy(aDx, aDy);
// Verify that the offset is within the defined coordinate space
if ((rect.x < 0) || (rect.y < 0)) {
NS_WARNING("invalid offset when offseting rect region");
return NS_ERROR_FAILURE;
}
// For the time being just remove it and add it back in. Because
// AddRectRegion() operates relative to the local coordinate space,
// translate from world coordinates to the local coordinate space
rect.MoveBy(-mX, -mY);
RemoveRegion(aFrame);
return AddRectRegion(aFrame, rect);
}
NS_IMETHODIMP
nsSpaceManager::RemoveRegion(nsIFrame* aFrame)
{
// Get the frame info associated with aFrame
FrameInfo* frameInfo = GetFrameInfoFor(aFrame);
if (nsnull == frameInfo) {
NS_WARNING("no region associated with aFrame");
return NS_ERROR_INVALID_ARG;
}
if (!frameInfo->rect.IsEmpty()) {
NS_ASSERTION(!mBandList.IsEmpty(), "no bands");
BandRect* band = mBandList.Head();
BandRect* prevBand = nsnull;
PRBool prevFoundMatchingRect = PR_FALSE;
// Iterate each band looking for rects tagged with aFrame
while (nsnull != band) {
BandRect* rect = band;
BandRect* prevRect = nsnull;
nscoord topOfBand = band->top;
PRBool foundMatchingRect = PR_FALSE;
PRBool prevIsSharedRect = PR_FALSE;
// Iterate each rect in the band
do {
PRBool isSharedRect = PR_FALSE;
if (rect->IsOccupiedBy(aFrame)) {
// Remember that we found a matching rect in this band
foundMatchingRect = PR_TRUE;
if (rect->numFrames > 1) {
// The band rect is occupied by more than one frame
rect->RemoveFrame(aFrame);
// Remember that this rect was being shared by more than one frame
// including aFrame
isSharedRect = PR_TRUE;
} else {
// The rect isn't shared so just delete it
BandRect* next = rect->Next();
rect->Remove();
if (rect == band) {
// The rect we're deleting is the start of the band
if (topOfBand == next->top) {
band = next;
} else {
band = nsnull;
}
}
delete rect;
rect = next;
// We don't need to try and coalesce adjacent rects in this case
prevRect = nsnull;
prevIsSharedRect = PR_FALSE;
continue;
}
}
// If we found a shared rect occupied by aFrame, then we need to try
// and coalesce adjacent rects
if (prevIsSharedRect || (isSharedRect && (nsnull != prevRect))) {
NS_ASSERTION(nsnull != prevRect, "no previous rect");
if ((prevRect->right == rect->left) && (prevRect->HasSameFrameList(rect))) {
// Modify the current rect's left edge, and delete the previous rect
rect->left = prevRect->left;
prevRect->Remove();
if (prevRect == band) {
// the rect we're deleting is the start of the band
band = rect;
}
delete prevRect;
}
}
// Get the next rect in the band
prevRect = rect;
prevIsSharedRect = isSharedRect;
rect = rect->Next();
} while (rect->top == topOfBand);
if (nsnull != band) {
// If we found a rect occupied by aFrame in this band or the previous band
// then try to join the two bands
if ((nsnull != prevBand) && (foundMatchingRect || prevFoundMatchingRect)) {
// Try and join this band with the previous band
JoinBands(band, prevBand);
}
}
// Move to the next band
prevFoundMatchingRect = foundMatchingRect;
prevBand = band;
band = (rect == &mBandList) ? nsnull : rect;
}
}
DestroyFrameInfo(frameInfo);
return NS_OK;
}
NS_IMETHODIMP
nsSpaceManager::ClearRegions()
{
ClearFrameInfo();
mBandList.Clear();
return NS_OK;
}
nsSpaceManager::FrameInfo*
nsSpaceManager::GetFrameInfoFor(nsIFrame* aFrame)
{
FrameInfo* result = nsnull;
if (nsnull != mFrameInfoMap) {
result = (FrameInfo*)PL_HashTableLookup(mFrameInfoMap, (const void*)aFrame);
}
return result;
}
nsSpaceManager::FrameInfo*
nsSpaceManager::CreateFrameInfo(nsIFrame* aFrame, const nsRect& aRect)
{
if (nsnull == mFrameInfoMap) {
mFrameInfoMap = PL_NewHashTable(17, NS_HashNumber, PL_CompareValues,
PL_CompareValues, nsnull, nsnull);
if (nsnull == mFrameInfoMap) {
return nsnull;
}
}
FrameInfo* frameInfo = new FrameInfo(aFrame, aRect);
if (nsnull != frameInfo) {
PL_HashTableAdd(mFrameInfoMap, (const void*)aFrame, frameInfo);
}
return frameInfo;
}
void
nsSpaceManager::DestroyFrameInfo(FrameInfo* aFrameInfo)
{
PL_HashTableRemove(mFrameInfoMap, (const void*)aFrameInfo->frame);
delete aFrameInfo;
}
/////////////////////////////////////////////////////////////////////////////
// FrameInfo
nsSpaceManager::FrameInfo::FrameInfo(nsIFrame* aFrame, const nsRect& aRect)
: frame(aFrame), rect(aRect)
{
}
/////////////////////////////////////////////////////////////////////////////
// BandRect
nsSpaceManager::BandRect::BandRect(nscoord aLeft,
nscoord aTop,
nscoord aRight,
nscoord aBottom,
nsIFrame* aFrame)
{
left = aLeft;
top = aTop;
right = aRight;
bottom = aBottom;
frame = aFrame;
numFrames = 1;
}
nsSpaceManager::BandRect::BandRect(nscoord aLeft,
nscoord aTop,
nscoord aRight,
nscoord aBottom,
nsVoidArray* aFrames)
{
left = aLeft;
top = aTop;
right = aRight;
bottom = aBottom;
frames = new nsVoidArray;
frames->operator=(*aFrames);
numFrames = frames->Count();
}
nsSpaceManager::BandRect::~BandRect()
{
if (numFrames > 1) {
delete frames;
}
}
nsSpaceManager::BandRect*
nsSpaceManager::BandRect::SplitVertically(nscoord aBottom)
{
NS_PRECONDITION((aBottom > top) && (aBottom < bottom), "bad argument");
// Create a new band rect for the bottom part
BandRect* bottomBandRect;
if (numFrames > 1) {
bottomBandRect = new BandRect(left, aBottom, right, bottom, frames);
} else {
bottomBandRect = new BandRect(left, aBottom, right, bottom, frame);
}
// This band rect becomes the top part, so adjust the bottom edge
bottom = aBottom;
return bottomBandRect;
}
nsSpaceManager::BandRect*
nsSpaceManager::BandRect::SplitHorizontally(nscoord aRight)
{
NS_PRECONDITION((aRight > left) && (aRight < right), "bad argument");
// Create a new band rect for the right part
BandRect* rightBandRect;
if (numFrames > 1) {
rightBandRect = new BandRect(aRight, top, right, bottom, frames);
} else {
rightBandRect = new BandRect(aRight, top, right, bottom, frame);
}
// This band rect becomes the left part, so adjust the right edge
right = aRight;
return rightBandRect;
}
PRBool
nsSpaceManager::BandRect::IsOccupiedBy(const nsIFrame* aFrame) const
{
PRBool result;
if (1 == numFrames) {
result = (frame == aFrame);
} else {
PRInt32 count = frames->Count();
result = PR_FALSE;
for (PRInt32 i = 0; i < count; i++) {
nsIFrame* f = (nsIFrame*)frames->ElementAt(i);
if (f == aFrame) {
result = PR_TRUE;
break;
}
}
}
return result;
}
void
nsSpaceManager::BandRect::AddFrame(const nsIFrame* aFrame)
{
if (1 == numFrames) {
nsIFrame* f = frame;
frames = new nsVoidArray;
frames->AppendElement(f);
}
numFrames++;
frames->AppendElement((void*)aFrame);
NS_POSTCONDITION(frames->Count() == numFrames, "bad frame count");
}
void
nsSpaceManager::BandRect::RemoveFrame(const nsIFrame* aFrame)
{
NS_PRECONDITION(numFrames > 1, "only one frame");
frames->RemoveElement((void*)aFrame);
numFrames--;
if (1 == numFrames) {
nsIFrame* f = (nsIFrame*)frames->ElementAt(0);
delete frames;
frame = f;
}
}
PRBool
nsSpaceManager::BandRect::HasSameFrameList(const BandRect* aBandRect) const
{
PRBool result;
// Check whether they're occupied by the same number of frames
if (numFrames != aBandRect->numFrames) {
result = PR_FALSE;
} else if (1 == numFrames) {
result = frame == aBandRect->frame;
} else {
result = PR_TRUE;
// For each frame occupying this band rect check whether it also occupies
// aBandRect
PRInt32 count = frames->Count();
for (PRInt32 i = 0; i < count; i++) {
nsIFrame* f = (nsIFrame*)frames->ElementAt(i);
if (-1 == aBandRect->frames->IndexOf(f)) {
result = PR_FALSE;
break;
}
}
}
return result;
}
/**
* Internal helper function that counts the number of rects in this band
* including the current band rect
*/
PRInt32
nsSpaceManager::BandRect::Length() const
{
PRInt32 len = 1;
BandRect* bandRect = Next();
// Because there's a header cell we know we'll either find the next band
// (which has a different y-offset) or the header cell which has an invalid
// y-offset
while (bandRect->top == top) {
len++;
bandRect = bandRect->Next();
}
return len;
}