gecko-dev/widget/nsPrimitiveHelpers.cpp
Neil Deakin 9c2e7458ba Bug 1776879, replace text/unicode for clipboard and drag and drop and use text/plain directly, r=edgar,mak,stransky,geckoview-reviewers,extension-reviewers,zombie,m_kato
Most usage is a straight replacement but gtk needs extra changes as it transfers plain text in UTF8 natively and needs to be converted into UTF16, and Windows uses single-byte characters for RTF and CF_HTML formats so we preserve this.

Differential Revision: https://phabricator.services.mozilla.com/D158587
2023-02-01 23:30:55 +00:00

194 lines
7.1 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/. */
//
// Part of the reason these routines are all in once place is so that as new
// data flavors are added that are known to be one-byte or two-byte strings, or
// even raw binary data, then we just have to go to one place to change how the
// data moves into/out of the primitives and native line endings.
//
// If you add new flavors that have special consideration (binary data or
// one-byte char* strings), please update all the helper classes in this file.
//
// For now, this is the assumption that we are making:
// - text/plain is always a char*
// - anything else is a char16_t*
//
#include "nsPrimitiveHelpers.h"
#include "mozilla/UniquePtr.h"
#include "nsComponentManagerUtils.h"
#include "nsCOMPtr.h"
#include "nsXPCOM.h"
#include "nsISupportsPrimitives.h"
#include "nsITransferable.h"
#include "nsLinebreakConverter.h"
#include "nsReadableUtils.h"
//
// CreatePrimitiveForData
//
// Given some data and the flavor it corresponds to, creates the appropriate
// nsISupports* wrapper for passing across IDL boundaries. Right now, everything
// creates a two-byte |nsISupportsString|, except for "text/plain" and native
// platform HTML (CF_HTML on win32)
//
void nsPrimitiveHelpers ::CreatePrimitiveForData(const nsACString& aFlavor,
const void* aDataBuff,
uint32_t aDataLen,
nsISupports** aPrimitive) {
if (!aPrimitive) return;
if (aFlavor.EqualsLiteral(kNativeHTMLMime) ||
aFlavor.EqualsLiteral(kRTFMime) ||
aFlavor.EqualsLiteral(kCustomTypesMime)) {
nsCOMPtr<nsISupportsCString> primitive =
do_CreateInstance(NS_SUPPORTS_CSTRING_CONTRACTID);
if (primitive) {
const char* start = reinterpret_cast<const char*>(aDataBuff);
primitive->SetData(Substring(start, start + aDataLen));
NS_ADDREF(*aPrimitive = primitive);
}
} else {
nsCOMPtr<nsISupportsString> primitive =
do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID);
if (primitive) {
if (aDataLen % 2) {
auto buffer = mozilla::MakeUnique<char[]>(aDataLen + 1);
if (!MOZ_LIKELY(buffer)) return;
memcpy(buffer.get(), aDataBuff, aDataLen);
buffer[aDataLen] = 0;
const char16_t* start = reinterpret_cast<const char16_t*>(buffer.get());
// recall that length takes length as characters, not bytes
primitive->SetData(Substring(start, start + (aDataLen + 1) / 2));
} else {
const char16_t* start = reinterpret_cast<const char16_t*>(aDataBuff);
// recall that length takes length as characters, not bytes
primitive->SetData(Substring(start, start + (aDataLen / 2)));
}
NS_ADDREF(*aPrimitive = primitive);
}
}
} // CreatePrimitiveForData
//
// CreatePrimitiveForCFHTML
//
// Platform specific CreatePrimitive, windows CF_HTML.
//
void nsPrimitiveHelpers ::CreatePrimitiveForCFHTML(const void* aDataBuff,
uint32_t* aDataLen,
nsISupports** aPrimitive) {
if (!aPrimitive) return;
nsCOMPtr<nsISupportsString> primitive =
do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID);
if (!primitive) return;
// We need to duplicate the input buffer, since the removal of linebreaks
// might reallocte it.
void* utf8 = moz_xmalloc(*aDataLen);
memcpy(utf8, aDataBuff, *aDataLen);
int32_t signedLen = static_cast<int32_t>(*aDataLen);
nsLinebreakHelpers::ConvertPlatformToDOMLinebreaks(true, &utf8, &signedLen);
*aDataLen = signedLen;
nsAutoString str(
NS_ConvertUTF8toUTF16(reinterpret_cast<const char*>(utf8), *aDataLen));
free(utf8);
*aDataLen = str.Length() * sizeof(char16_t);
primitive->SetData(str);
NS_ADDREF(*aPrimitive = primitive);
}
//
// CreateDataFromPrimitive
//
// Given a nsISupports* primitive and the flavor it represents, creates a new
// data buffer with the data in it. This data will be null terminated, but the
// length parameter does not reflect that.
//
void nsPrimitiveHelpers::CreateDataFromPrimitive(const nsACString& aFlavor,
nsISupports* aPrimitive,
void** aDataBuff,
uint32_t* aDataLen) {
if (!aDataBuff) return;
*aDataBuff = nullptr;
*aDataLen = 0;
if (aFlavor.EqualsLiteral(kCustomTypesMime)) {
nsCOMPtr<nsISupportsCString> plainText(do_QueryInterface(aPrimitive));
if (plainText) {
nsAutoCString data;
plainText->GetData(data);
*aDataBuff = ToNewCString(data);
*aDataLen = data.Length() * sizeof(char);
}
} else {
nsCOMPtr<nsISupportsString> doubleByteText(do_QueryInterface(aPrimitive));
if (doubleByteText) {
nsAutoString data;
doubleByteText->GetData(data);
*aDataBuff = ToNewUnicode(data);
*aDataLen = data.Length() * sizeof(char16_t);
}
}
}
//
// ConvertPlatformToDOMLinebreaks
//
// Given some data, convert from the platform linebreaks into the LF expected by
// the DOM. This will attempt to convert the data in place, but the buffer may
// still need to be reallocated regardless (disposing the old buffer is taken
// care of internally, see the note below).
//
// NOTE: this assumes that it can use 'free' to dispose of the old buffer.
//
nsresult nsLinebreakHelpers ::ConvertPlatformToDOMLinebreaks(
bool aIsSingleByteChars, void** ioData, int32_t* ioLengthInBytes) {
NS_ASSERTION(ioData && *ioData && ioLengthInBytes, "Bad Params");
if (!(ioData && *ioData && ioLengthInBytes)) return NS_ERROR_INVALID_ARG;
nsresult retVal = NS_OK;
// RTF and CF_HTML on Windows are transfered as single-byte characters.
if (aIsSingleByteChars) {
char* buffAsChars = reinterpret_cast<char*>(*ioData);
char* oldBuffer = buffAsChars;
retVal = nsLinebreakConverter::ConvertLineBreaksInSitu(
&buffAsChars, nsLinebreakConverter::eLinebreakAny,
nsLinebreakConverter::eLinebreakContent, *ioLengthInBytes,
ioLengthInBytes);
if (NS_SUCCEEDED(retVal)) {
if (buffAsChars != oldBuffer) // check if buffer was reallocated
free(oldBuffer);
*ioData = buffAsChars;
}
} else {
char16_t* buffAsUnichar = reinterpret_cast<char16_t*>(*ioData);
char16_t* oldBuffer = buffAsUnichar;
int32_t newLengthInChars;
retVal = nsLinebreakConverter::ConvertUnicharLineBreaksInSitu(
&buffAsUnichar, nsLinebreakConverter::eLinebreakAny,
nsLinebreakConverter::eLinebreakContent,
*ioLengthInBytes / sizeof(char16_t), &newLengthInChars);
if (NS_SUCCEEDED(retVal)) {
if (buffAsUnichar != oldBuffer) // check if buffer was reallocated
free(oldBuffer);
*ioData = buffAsUnichar;
*ioLengthInBytes = newLengthInChars * sizeof(char16_t);
}
}
return retVal;
} // ConvertPlatformToDOMLinebreaks