--- a/ganeswidgets/src/HgScrollBufferManager.cpp Fri Jun 11 14:43:11 2010 +0300
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,589 +0,0 @@
-/*
-* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
-* All rights reserved.
-* This component and the accompanying materials are made available
-* under the terms of "Eclipse Public License v1.0"
-* which accompanies this distribution, and is available
-* at the URL "http://www.eclipse.org/legal/epl-v10.html".
-*
-* Initial Contributors:
-* Nokia Corporation - initial contribution.
-*
-* Contributors:
-*
-* Description:
-*
-*/
-
-
-#include <QTimer>
-
-#include "HgScrollBufferManager.h"
-#include "trace.h"
-
-// -----------------------------------------------------------------------------
-// HgScrollBufferManager::HgScrollBufferManager()
-// -----------------------------------------------------------------------------
-//
-HgScrollBufferManager::HgScrollBufferManager(
- int bufferSize,
- int bufferTreshold,
- int initialPosition,
- int totalCount )
-: mBufferSize( bufferSize ),
- mBufferTreshold( bufferTreshold ),
- mBufferPosition( initialPosition ),
- mDiff(0),
- mTotalCount( totalCount ),
- mResetOrdered(false),
- mRequestStart(0),
- mRequestCount(0),
- mReleaseStart(0),
- mReleaseCount(0),
- mFirstTime(true)
- {
- init();
- }
-
-// -----------------------------------------------------------------------------
-// HgScrollBufferManager::init()
-// -----------------------------------------------------------------------------
-//
-void HgScrollBufferManager::init()
- {
- mResetOrdered = ETrue;
- mTimer.setSingleShot(true);
- connect(&mTimer, SIGNAL(timeout()), this, SLOT(timeout()));
- }
-
-// -----------------------------------------------------------------------------
-// HgScrollBufferManager::~HgScrollBufferManager()
-// -----------------------------------------------------------------------------
-//
-HgScrollBufferManager::~HgScrollBufferManager()
- {
- mTimer.stop();
- }
-
-// -----------------------------------------------------------------------------
-// HgScrollBufferManager::resetBuffer()
-// -----------------------------------------------------------------------------
-//
-void HgScrollBufferManager::resetBuffer( int aPosition, int totalCount )
- {
- if( !mResetOrdered )
- {
- // release Old buffer
- mReleaseStart = mBufferPosition;
- mReleaseCount = mBufferSize;
- }
-
- // set position and count
- mBufferPosition = aPosition - (mBufferSize / 2);
- mTotalCount = totalCount;
- mDiff = 0;
-
- if( mBufferPosition + mBufferSize > mTotalCount - 1 )
- {
- mBufferPosition = mTotalCount - mBufferSize;
- }
-
- if(mBufferPosition < 0 )
- {
- mBufferPosition = 0;
- }
-
- //request new Buffer
- mRequestStart = mBufferPosition;
- mRequestCount = mBufferSize;
- mResetOrdered = ETrue;
- asyncUpdate();
- }
-
-void HgScrollBufferManager::scrollPositionChanged( int newPosition )
- {
- // If all the items fit in the buffer no need to move the buffer.
- if( mTotalCount <= mBufferSize ) return;
-
- bool forceUpdate = EFalse;
- newPosition -= mBufferSize / 2; // normalize index to Buffer start
-
- if(newPosition < 0)
- {
- newPosition = 0;
- forceUpdate = ETrue;
- }
- else if( newPosition > mTotalCount - mBufferSize )
- {
- newPosition = mTotalCount - mBufferSize;
- forceUpdate = ETrue;
- }
-
- mDiff = mBufferPosition - newPosition;
-
- // Too large change reset whole buffer
- if( mDiff >= mBufferSize || -mDiff >= mBufferSize || mResetOrdered )
- {
- resetBuffer(newPosition + (mBufferSize/2), mTotalCount );
- }
- // Move Up
- else if( mDiff >= mBufferTreshold )
- {
- mRequestCount = mDiff;
- mReleaseCount = mDiff;
- asyncUpdate();
- }
- // Move Down
- else if( -mDiff >= mBufferTreshold )
- {
- mRequestCount = -mDiff;
- mReleaseCount = -mDiff;
- asyncUpdate();
- }
- // Top or bottom has been reached
- else if( forceUpdate && mDiff )
- {
- int diff = mDiff < 0 ? -mDiff : mDiff;
- mRequestCount = diff;
- mReleaseCount = diff;
- asyncUpdate();
- }
- }
-
-void HgScrollBufferManager::timeout()
-{
- mFirstTime = false;
-
- if(mResetOrdered)
- {
- mResetOrdered = EFalse;
- }
- else
- {
- if(mDiff < 0)
- {
- mReleaseStart = mBufferPosition;
- mRequestStart = mBufferPosition + mBufferSize;
- }
- else if( mDiff > 0)
- {
- mReleaseStart = mBufferPosition + mBufferSize - mDiff;
- mRequestStart = mBufferPosition - mDiff;
- }
- }
-
- // Release
- int end = mReleaseStart + mReleaseCount < mTotalCount ?
- mReleaseStart + mReleaseCount: mTotalCount;
- end--;
- if(end >= mReleaseStart )
- {
- emit releaseItems( mReleaseStart, end );
- }
-
- mReleaseCount = 0;
-
- // Request
- end = mRequestStart + mRequestCount < mTotalCount ?
- mRequestStart + mRequestCount : mTotalCount;
-
- end--;
- if(end >= mRequestStart )
- {
- emit requestItems( mRequestStart, end );
- }
-
- mRequestCount = 0;
-
- // Move Buffer
- mBufferPosition -= mDiff;
- // Reset Diff
- mDiff = 0;
-}
-
-bool HgScrollBufferManager::positionInsideBuffer( int position )
-{
- return position >= mBufferPosition && position <= (mBufferPosition+mBufferSize);
-}
-
-void HgScrollBufferManager::asyncUpdate()
-{
- if (!mTimer.isActive() && mFirstTime) {
- mTimer.start(0);
- } else if (!mTimer.isActive()){
- timeout();
- }
-}
-
-void HgScrollBufferManager::currentBuffer(int& bufferStart, int& bufferEnd)
-{
- bufferStart = mBufferPosition;
- bufferEnd = mBufferPosition+mBufferSize > mTotalCount-1 ?
- mTotalCount-1 : mBufferPosition+mBufferSize;
-}
-
-void HgScrollBufferManager::addItems(int start, int end)
-{
- FUNC_LOG;
-
- mTotalCount += (end-start+1);
- int lastBufferItem = mBufferPosition+mBufferSize-1;
-
- if (start < mBufferPosition) {
- simpleAddItems(start, end);
- // New items push the buffer forward, items inside the buffer do not change
- }
- // Check buffer higher limit
- else if (start <= lastBufferItem && end > lastBufferItem) {
- simpleAddItems(start, lastBufferItem);
- // Items added after the buffer are ignored
- }
- else {
- simpleAddItems(start, end);
- }
-}
-
-void HgScrollBufferManager::removeItems(int start, int end)
-{
- FUNC_LOG;
-
- int lastBufferItem = mBufferPosition+mBufferSize-1;
- int removedItemCount = end-start+1;
-
- if (mTotalCount < mBufferSize) {
- // Do nothing
- }
- else if (start > lastBufferItem) {
- // Do nothing
- }
- else if (end < mBufferPosition) {
- mTotalCount = mTotalCount-removedItemCount;
- simpleRemoveItems(start, end);
- }
- else if (start < mBufferPosition && end > lastBufferItem) {
- mTotalCount = mTotalCount-removedItemCount;
- mBufferPosition = qBound(0, mBufferPosition, mTotalCount-mBufferSize);
- resetBuffer(mBufferPosition, mTotalCount);
- }
- // Check buffer higher limit
- else if (start <= lastBufferItem && end > lastBufferItem) {
- mTotalCount = mTotalCount-(end-lastBufferItem);
- simpleRemoveItems(lastBufferItem+1, end);
- mTotalCount = mTotalCount-(lastBufferItem-start+1);
- simpleRemoveItems(start, lastBufferItem);
- // Order does matter
- mTotalCount = mTotalCount-(end-lastBufferItem);
- simpleRemoveItems(lastBufferItem+1, end);
- mTotalCount = mTotalCount-(lastBufferItem-start+1);
- simpleRemoveItems(start, lastBufferItem);
- }
- // Check buffer lower limit
- else if (start < mBufferPosition && end >= mBufferPosition) {
- // Order does matter
- mTotalCount = mTotalCount-(end-mBufferPosition+1);
- simpleRemoveItems(mBufferPosition, end);
- mTotalCount = mTotalCount-(mBufferPosition-start);
- simpleRemoveItems(start, mBufferPosition-1);
- }
- else {
- mTotalCount = mTotalCount-removedItemCount;
- simpleRemoveItems(start, end);
- }
-}
-
-void HgScrollBufferManager::moveItems(int start, int end, int target)
-{
- int lastBufferItem = mBufferPosition+mBufferSize-1;
-
- INFO("Move" << start << "-" << end << "to" << target << ",buffer:" << mBufferPosition << "-" << lastBufferItem << "total count:" << mTotalCount);
-
- if (mTotalCount < mBufferSize) {
- // Do nothing
- }
- else if (start < mBufferPosition && end > lastBufferItem) {
- resetBuffer(mBufferPosition, mTotalCount);
- }
- else if (start > lastBufferItem && target > lastBufferItem) {
- // Do nothing
- }
- else if (start > lastBufferItem && target < mBufferPosition) {
- simpleAddItems(start, end);
- }
- else if (end < mBufferPosition && target < mBufferPosition) {
- // Do nothing
- }
- else if (end < mBufferPosition && target > lastBufferItem) {
- simpleRemoveItems(start, end);
- }
- else if (start >= mBufferPosition && end <= lastBufferItem &&
- target >= mBufferPosition && target <= lastBufferItem) {
- // Do nothing
- }
- else {
- // Rare and complicated use cases: reset the whole buffer
- resetBuffer(mBufferPosition, mTotalCount);
- }
-}
-
-void HgScrollBufferManager::flushRequestBuffers()
-{
- FUNC_LOG;
-
- qSort(mReleaseBuffer);
- int releaseCount = mReleaseBuffer.count();
- int lastReleased = -1;
- for (int i = 0; i < releaseCount; i++) {
- UpdatePair update = mReleaseBuffer.at(i);
- emit releaseItems(qMax(lastReleased+1, update.start()), update.end());
- lastReleased = update.end();
- }
- mReleaseBuffer.clear();
-
- qSort(mRequestBuffer);
- int requestCount = mRequestBuffer.count();
- int lastRequested = -1;
- for (int i = 0; i < requestCount; i++) {
- UpdatePair update = mRequestBuffer.at(i);
- emit requestItems(qMax(lastRequested+1, update.start()), update.end());
- lastRequested = update.end();
- }
- mRequestBuffer.clear();
-}
-
-int HgScrollBufferManager::changeBufferPosition(int newPos)
-{
- FUNC_LOG;
- INFO("Change buffer position to" << newPos << "total count:" << mTotalCount);
- HANDLE_ERROR_BOOL((newPos >= 0));
- HANDLE_ERROR_BOOL((newPos+mBufferSize <= mTotalCount));
-
- int bufferShift = newPos-mBufferPosition;
- if (bufferShift > 0) {
- mRequestBuffer.shiftRight(mBufferPosition, bufferShift);
- mReleaseBuffer.shiftRight(mBufferPosition, bufferShift);
- }
- else if (bufferShift < 0) {
- mRequestBuffer.shiftLeft(mBufferPosition, -bufferShift);
- mReleaseBuffer.shiftLeft(mBufferPosition, -bufferShift);
- }
- mBufferPosition = newPos;
- return bufferShift;
-}
-
-/**
- This function manages only simple item additions: all items are either
- outside the buffer or inside it.
- Firs call prepare, then update model, then call fecth.
-*/
-void HgScrollBufferManager::simpleAddItems(int start, int end)
-{
- FUNC_LOG;
-
- int lastBufferItem = mBufferPosition+mBufferSize-1;
- int numAddedItems = end-start+1; // [start, end] inclusive
-
- if (mTotalCount < mBufferSize) {
- appendRequestBuffer(start, numAddedItems);
- }
- else if (start > lastBufferItem) {
- // Do nothing
- }
- else if (start <= mBufferPosition) {
- changeBufferPosition(mBufferPosition+numAddedItems);
- // No need to fetch items, the indexes just change
- }
- else {
- // free from end
- appendReleaseBuffer(lastBufferItem+1-numAddedItems, numAddedItems);
- mReleaseBuffer.shiftRight(start, numAddedItems);
- mRequestBuffer.shiftRight(start, numAddedItems);
- appendRequestBuffer(start, numAddedItems);
- }
-}
-
-/**
- This function manages only simple item removals: all items are either
- outside the buffer or inside it.
- Firs call prepare, then update model, then call fecth.
-*/
-void HgScrollBufferManager::simpleRemoveItems(int start, int end)
-{
- FUNC_LOG;
-
- int lastBufferItem = mBufferPosition+mBufferSize-1;
- int numRemovedItems = end-start+1; // [start, end] inclusive
-
- if (start > lastBufferItem) {
- // Do nothing
- }
- else if (end < mBufferPosition) {
- changeBufferPosition(qMax(0, mBufferPosition-numRemovedItems));
- // No need to fetch items, the indexes just change
- }
- else {
- if (mTotalCount < mBufferPosition+mBufferSize) {
- // Buffer is at the end of items
- int bufferShift = changeBufferPosition(qMax(0, mTotalCount-mBufferSize));
- // Fetch from beginning
- // Releasing removed items has been done outside this class
- appendRequestBuffer(mBufferPosition, qAbs(bufferShift));
- }
- else {
- // Fetch from end
- appendRequestBuffer(lastBufferItem+1-numRemovedItems, numRemovedItems);
- }
- }
-}
-
-void HgScrollBufferManager::appendRequestBuffer(int start, int count)
-{
- FUNC_LOG;
- INFO("Request items" << start << ":" << count)
-
- mRequestBuffer.add(start, count);
- mReleaseBuffer.remove(start, count);
-}
-
-void HgScrollBufferManager::appendReleaseBuffer(int start, int count)
-{
- FUNC_LOG;
- INFO("Release items" << start << ":" << count)
-
- mReleaseBuffer.add(start, count);
- mRequestBuffer.remove(start, count);
-}
-
-UpdatePair::UpdatePair(int start, int count) : mStart(start), mCount(count)
-{
- HANDLE_ERROR_BOOL(mCount > 0);
-}
-
-int UpdatePair::start() const
-{
- return mStart;
-}
-
-int UpdatePair::end() const
-{
- return mStart+mCount-1;
-}
-
-bool UpdatePair::adjacent(int start, int count) const
-{
- if (start+count < mStart) return false;
- if (start > mStart+mCount) return false;
- return true;
-}
-
-bool UpdatePair::contains(const UpdatePair &other) const
-{
- if (other.mStart+other.mCount-1 < mStart) return false;
- if (other.mStart > mStart+mCount-1) return false;
- return true;
-}
-
-void UpdatePair::extend(int start, int count)
-{
- int end = qMax(mStart+mCount, start+count);
- mStart = qMin(mStart, start);
- mCount = end-mStart;
- INFO("Pair extended to:" << mStart << ":" << mCount);
-}
-
-void UpdatePair::subtract(int start, int count)
-{
- int end = qMin(mStart+mCount, start+count);
- mStart = qMax(mStart, start);
- mCount = end-mStart;
- INFO("Pair reduced to:" << mStart << ":" << mCount);
-}
-
-void UpdatePair::shiftRight(int count)
-{
- mStart += count;
- INFO("Pair shifted to:" << mStart << ":" << mCount);
-}
-
-void UpdatePair::shiftLeft(int count)
-{
- mStart -= count;
- HANDLE_ERROR_BOOL((mStart >= 0));
- INFO("Pair shifted to:" << mStart << ":" << mCount);
-}
-
-bool UpdatePair::operator== (const UpdatePair &other) const
-{
- return mStart == other.mStart && mCount == other.mCount;
-}
-
-bool UpdatePair::operator< (const UpdatePair &other) const
-{
- return (mStart < other.mStart || mStart == other.mStart && mCount < other.mCount);
-}
-
-UpdateBuffer::UpdateBuffer()
-{
- FUNC_LOG;
-}
-
-void UpdateBuffer::add(int start, int count)
-{
- FUNC_LOG;
-
- int itemCount = this->count();
- for (int i = 0; i < itemCount; i++) {
- if (at(i).contains(UpdatePair(start, count))) {
- // It is already there
- return;
- }
- if (at(i).adjacent(start, count)) {
- (*this)[i].extend(start, count);
- return;
- }
- }
- append(UpdatePair(start, count));
-}
-
-void UpdateBuffer::remove(int start, int count)
-{
- FUNC_LOG;
-
- int itemCount = this->count();
- for (int i = itemCount-1; i >= 0; i--) {
- UpdatePair pair = at(i);
- UpdatePair comp = UpdatePair(start, count);
- if (comp.contains(pair)) {
- INFO("Removing pair" << pair.start() << "-" << pair.end());
- removeAt(i);
- }
- else if (pair.contains(comp)) {
- // Subtraction from middle is not applicable in mediawall use cases
- (*this)[i].subtract(start, count);
- }
- // Item may be present in multiple pairs.
- }
-}
-
-void UpdateBuffer::shiftRight(int startingFrom, int amount)
-{
- FUNC_LOG;
-
- int itemCount = this->count();
- for (int i = 0; i < itemCount; i++) {
- if (at(i).start() >= startingFrom) {
- (*this)[i].shiftRight(amount);
- }
- }
-}
-
-void UpdateBuffer::shiftLeft(int startingFrom, int amount)
-{
- FUNC_LOG;
-
- int itemCount = this->count();
- for (int i = 0; i < itemCount; i++) {
- if (at(i).start() >= startingFrom) {
- (*this)[i].shiftLeft(amount);
- }
- }
-}