gecko/editor/libeditor/base/PlaceholderTxn.cpp
2007-07-02 07:01:27 -07:00

279 lines
9.2 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla 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/MPL/
*
* 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 the Initial Developer are Copyright (C) 1998-1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Pierre Phaneuf <pp@ludusdesign.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "PlaceholderTxn.h"
#include "nsEditor.h"
#include "IMETextTxn.h"
PlaceholderTxn::PlaceholderTxn() : EditAggregateTxn(),
mAbsorb(PR_TRUE),
mForwarding(nsnull),
mIMETextTxn(nsnull),
mCommitted(PR_FALSE),
mStartSel(nsnull),
mEndSel(),
mEditor(nsnull)
{
}
NS_IMPL_ISUPPORTS_INHERITED2(PlaceholderTxn, EditAggregateTxn,
nsIAbsorbingTransaction, nsISupportsWeakReference)
NS_IMETHODIMP PlaceholderTxn::Init(nsIAtom *aName, nsSelectionState *aSelState, nsIEditor *aEditor)
{
if (!aEditor || !aSelState) return NS_ERROR_NULL_POINTER;
mName = aName;
mStartSel = aSelState;
mEditor = aEditor;
return NS_OK;
}
NS_IMETHODIMP PlaceholderTxn::DoTransaction(void)
{
return NS_OK;
}
NS_IMETHODIMP PlaceholderTxn::UndoTransaction(void)
{
// undo txns
nsresult res = EditAggregateTxn::UndoTransaction();
if (NS_FAILED(res)) return res;
if (!mStartSel) return NS_ERROR_NULL_POINTER;
// now restore selection
nsCOMPtr<nsISelection> selection;
res = mEditor->GetSelection(getter_AddRefs(selection));
if (NS_FAILED(res)) return res;
if (!selection) return NS_ERROR_NULL_POINTER;
return mStartSel->RestoreSelection(selection);
}
NS_IMETHODIMP PlaceholderTxn::RedoTransaction(void)
{
// redo txns
nsresult res = EditAggregateTxn::RedoTransaction();
if (NS_FAILED(res)) return res;
// now restore selection
nsCOMPtr<nsISelection> selection;
res = mEditor->GetSelection(getter_AddRefs(selection));
if (NS_FAILED(res)) return res;
if (!selection) return NS_ERROR_NULL_POINTER;
return mEndSel.RestoreSelection(selection);
}
NS_IMETHODIMP PlaceholderTxn::Merge(nsITransaction *aTransaction, PRBool *aDidMerge)
{
if (!aDidMerge || !aTransaction) return NS_ERROR_NULL_POINTER;
// set out param default value
*aDidMerge=PR_FALSE;
if (mForwarding)
{
NS_NOTREACHED("tried to merge into a placeholder that was in forwarding mode!");
return NS_ERROR_FAILURE;
}
// check to see if aTransaction is one of the editor's
// private transactions. If not, we want to avoid merging
// the foreign transaction into our placeholder since we
// don't know what it does.
nsCOMPtr<nsPIEditorTransaction> pTxn = do_QueryInterface(aTransaction);
if (!pTxn) return NS_OK; // it's foreign so just bail!
EditTxn *editTxn = (EditTxn*)aTransaction; //XXX: hack, not safe! need nsIEditTransaction!
// determine if this incoming txn is a placeholder txn
nsCOMPtr<nsIAbsorbingTransaction> plcTxn;// = do_QueryInterface(editTxn);
// can't do_QueryInterface() above due to our broken transaction interfaces.
// instead have to brute it below. ugh.
editTxn->QueryInterface(NS_GET_IID(nsIAbsorbingTransaction), getter_AddRefs(plcTxn));
// we are absorbing all txn's if mAbsorb is lit.
if (mAbsorb)
{
nsRefPtr<IMETextTxn> otherTxn;
if (NS_SUCCEEDED(aTransaction->QueryInterface(IMETextTxn::GetCID(), getter_AddRefs(otherTxn))) && otherTxn)
{
// special handling for IMETextTxn's: they need to merge with any previous
// IMETextTxn in this placeholder, if possible.
if (!mIMETextTxn)
{
// this is the first IME txn in the placeholder
mIMETextTxn =otherTxn;
AppendChild(editTxn);
}
else
{
PRBool didMerge;
mIMETextTxn->Merge(otherTxn, &didMerge);
if (!didMerge)
{
// it wouldn't merge. Earlier IME txn is already commited and will
// not absorb further IME txns. So just stack this one after it
// and remember it as a candidate for further merges.
mIMETextTxn =otherTxn;
AppendChild(editTxn);
}
}
}
else if (!plcTxn) // see bug 171243: just drop incoming placeholders on the floor.
{ // their children will be swallowed by this preexisting one.
AppendChild(editTxn);
}
*aDidMerge = PR_TRUE;
// RememberEndingSelection();
// efficiency hack: no need to remember selection here, as we haven't yet
// finished the inital batch and we know we will be told when the batch ends.
// we can remeber the selection then.
}
else
{ // merge typing or IME or deletion transactions if the selection matches
if (((mName.get() == nsEditor::gTypingTxnName) ||
(mName.get() == nsEditor::gIMETxnName) ||
(mName.get() == nsEditor::gDeleteTxnName))
&& !mCommitted )
{
nsCOMPtr<nsIAbsorbingTransaction> plcTxn;// = do_QueryInterface(editTxn);
// can't do_QueryInterface() above due to our broken transaction interfaces.
// instead have to brute it below. ugh.
editTxn->QueryInterface(NS_GET_IID(nsIAbsorbingTransaction), getter_AddRefs(plcTxn));
if (plcTxn)
{
nsCOMPtr<nsIAtom> atom;
plcTxn->GetTxnName(getter_AddRefs(atom));
if (atom && (atom == mName))
{
// check if start selection of next placeholder matches
// end selection of this placeholder
PRBool isSame;
plcTxn->StartSelectionEquals(&mEndSel, &isSame);
if (isSame)
{
mAbsorb = PR_TRUE; // we need to start absorbing again
plcTxn->ForwardEndBatchTo(this);
// AppendChild(editTxn);
// see bug 171243: we don't need to merge placeholders
// into placeholders. We just reactivate merging in the pre-existing
// placeholder and drop the new one on the floor. The EndPlaceHolderBatch()
// call on the new placeholder will be forwarded to this older one.
RememberEndingSelection();
*aDidMerge = PR_TRUE;
}
}
}
}
}
return NS_OK;
}
NS_IMETHODIMP PlaceholderTxn::GetTxnDescription(nsAString& aString)
{
aString.AssignLiteral("PlaceholderTxn: ");
if (mName)
{
nsAutoString name;
mName->ToString(name);
aString += name;
}
return NS_OK;
}
NS_IMETHODIMP PlaceholderTxn::GetTxnName(nsIAtom **aName)
{
return GetName(aName);
}
NS_IMETHODIMP PlaceholderTxn::StartSelectionEquals(nsSelectionState *aSelState, PRBool *aResult)
{
// determine if starting selection matches the given selection state.
// note that we only care about collapsed selections.
if (!aResult || !aSelState) return NS_ERROR_NULL_POINTER;
if (!mStartSel->IsCollapsed() || !aSelState->IsCollapsed())
{
*aResult = PR_FALSE;
return NS_OK;
}
*aResult = mStartSel->IsEqual(aSelState);
return NS_OK;
}
NS_IMETHODIMP PlaceholderTxn::EndPlaceHolderBatch()
{
mAbsorb = PR_FALSE;
if (mForwarding)
{
nsCOMPtr<nsIAbsorbingTransaction> plcTxn = do_QueryReferent(mForwarding);
if (plcTxn) plcTxn->EndPlaceHolderBatch();
}
// remember our selection state.
return RememberEndingSelection();
}
NS_IMETHODIMP PlaceholderTxn::ForwardEndBatchTo(nsIAbsorbingTransaction *aForwardingAddress)
{
mForwarding = do_GetWeakReference(aForwardingAddress);
return NS_OK;
}
NS_IMETHODIMP PlaceholderTxn::Commit()
{
mCommitted = PR_TRUE;
return NS_OK;
}
NS_IMETHODIMP PlaceholderTxn::RememberEndingSelection()
{
nsCOMPtr<nsISelection> selection;
nsresult res = mEditor->GetSelection(getter_AddRefs(selection));
if (NS_FAILED(res)) return res;
if (!selection) return NS_ERROR_NULL_POINTER;
return mEndSel.SaveSelection(selection);
}