gecko-dev/editor/libeditor/PlaceholderTxn.cpp

263 lines
7.8 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "PlaceholderTxn.h"
#include "nsEditor.h"
#include "IMETextTxn.h"
#include "nsGkAtoms.h"
#include "mozilla/dom/Selection.h"
#include "nsQueryObject.h"
using namespace mozilla;
using namespace mozilla::dom;
PlaceholderTxn::PlaceholderTxn() : EditAggregateTxn(),
mAbsorb(true),
mForwarding(nullptr),
mIMETextTxn(nullptr),
mCommitted(false),
mStartSel(nullptr),
mEndSel(),
mEditor(nullptr)
{
}
PlaceholderTxn::~PlaceholderTxn()
{
}
NS_IMPL_CYCLE_COLLECTION_CLASS(PlaceholderTxn)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(PlaceholderTxn,
EditAggregateTxn)
tmp->mStartSel->DoUnlink();
tmp->mEndSel.DoUnlink();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(PlaceholderTxn,
EditAggregateTxn)
tmp->mStartSel->DoTraverse(cb);
tmp->mEndSel.DoTraverse(cb);
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(PlaceholderTxn)
NS_INTERFACE_MAP_ENTRY(nsIAbsorbingTransaction)
NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
NS_INTERFACE_MAP_END_INHERITING(EditAggregateTxn)
NS_IMPL_ADDREF_INHERITED(PlaceholderTxn, EditAggregateTxn)
NS_IMPL_RELEASE_INHERITED(PlaceholderTxn, EditAggregateTxn)
NS_IMETHODIMP
PlaceholderTxn::Init(nsIAtom* aName, nsSelectionState* aSelState,
nsEditor* aEditor)
{
NS_ENSURE_TRUE(aEditor && aSelState, 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();
NS_ENSURE_SUCCESS(res, res);
NS_ENSURE_TRUE(mStartSel, NS_ERROR_NULL_POINTER);
// now restore selection
nsRefPtr<Selection> selection = mEditor->GetSelection();
NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);
return mStartSel->RestoreSelection(selection);
}
NS_IMETHODIMP PlaceholderTxn::RedoTransaction(void)
{
// redo txns
nsresult res = EditAggregateTxn::RedoTransaction();
NS_ENSURE_SUCCESS(res, res);
// now restore selection
nsRefPtr<Selection> selection = mEditor->GetSelection();
NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);
return mEndSel.RestoreSelection(selection);
}
NS_IMETHODIMP PlaceholderTxn::Merge(nsITransaction *aTransaction, bool *aDidMerge)
{
NS_ENSURE_TRUE(aDidMerge && aTransaction, NS_ERROR_NULL_POINTER);
// set out param default value
*aDidMerge=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);
NS_ENSURE_TRUE(pTxn, 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_QueryObject(editTxn);
// we are absorbing all txn's if mAbsorb is lit.
if (mAbsorb)
{
nsRefPtr<IMETextTxn> otherTxn = do_QueryObject(aTransaction);
if (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
{
bool didMerge;
mIMETextTxn->Merge(otherTxn, &didMerge);
if (!didMerge)
{
// it wouldn't merge. Earlier IME txn is already committed 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 = true;
// RememberEndingSelection();
// efficiency hack: no need to remember selection here, as we haven't yet
// finished the initial 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() == nsGkAtoms::TypingTxnName) ||
(mName.get() == nsGkAtoms::IMETxnName) ||
(mName.get() == nsGkAtoms::DeleteTxnName))
&& !mCommitted )
{
nsCOMPtr<nsIAbsorbingTransaction> plcTxn = do_QueryObject(editTxn);
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
bool isSame;
plcTxn->StartSelectionEquals(&mEndSel, &isSame);
if (isSame)
{
mAbsorb = 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 = 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, bool *aResult)
{
// determine if starting selection matches the given selection state.
// note that we only care about collapsed selections.
NS_ENSURE_TRUE(aResult && aSelState, NS_ERROR_NULL_POINTER);
if (!mStartSel->IsCollapsed() || !aSelState->IsCollapsed())
{
*aResult = false;
return NS_OK;
}
*aResult = mStartSel->IsEqual(aSelState);
return NS_OK;
}
NS_IMETHODIMP PlaceholderTxn::EndPlaceHolderBatch()
{
mAbsorb = 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 = true;
return NS_OK;
}
nsresult PlaceholderTxn::RememberEndingSelection()
{
nsRefPtr<Selection> selection = mEditor->GetSelection();
NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);
mEndSel.SaveSelection(selection);
return NS_OK;
}