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| 1 | +// Copyright 2013 The Flutter Authors. All rights reserved. |
| 2 | +// Use of this source code is governed by a BSD-style license that can be |
| 3 | +// found in the LICENSE file. |
| 4 | + |
| 5 | +// This file contains the implementations of any class in the wrapper that |
| 6 | +// - is not fully inline, and |
| 7 | +// - is necessary for all clients of the wrapper (either app or plugin). |
| 8 | +// It exists instead of the usual structure of having some_class_name.cc files |
| 9 | +// so that changes to the set of things that need non-header implementations |
| 10 | +// are not breaking changes for the template. |
| 11 | +// |
| 12 | +// If https://github.com/flutter/flutter/issues/57146 is fixed, this can be |
| 13 | +// removed in favor of the normal structure since templates will no longer |
| 14 | +// manually include files. |
| 15 | + |
| 16 | +#include <assert.h> |
| 17 | + |
| 18 | +#include <iostream> |
| 19 | + |
| 20 | +#include "binary_messenger_impl.h" |
| 21 | +#include "include/flutter/engine_method_result.h" |
| 22 | + |
| 23 | +namespace flutter { |
| 24 | + |
| 25 | +// ========== binary_messenger_impl.h ========== |
| 26 | + |
| 27 | +namespace { |
| 28 | +// Passes |message| to |user_data|, which must be a BinaryMessageHandler, along |
| 29 | +// with a BinaryReply that will send a response on |message|'s response handle. |
| 30 | +// |
| 31 | +// This serves as an adaptor between the function-pointer-based message callback |
| 32 | +// interface provided by the C API and the std::function-based message handler |
| 33 | +// interface of BinaryMessenger. |
| 34 | +void ForwardToHandler(FlutterDesktopMessengerRef messenger, |
| 35 | + const FlutterDesktopMessage* message, |
| 36 | + void* user_data) { |
| 37 | + auto* response_handle = message->response_handle; |
| 38 | + BinaryReply reply_handler = [messenger, response_handle]( |
| 39 | + const uint8_t* reply, |
| 40 | + size_t reply_size) mutable { |
| 41 | + if (!response_handle) { |
| 42 | + std::cerr << "Error: Response can be set only once. Ignoring " |
| 43 | + "duplicate response." |
| 44 | + << std::endl; |
| 45 | + return; |
| 46 | + } |
| 47 | + FlutterDesktopMessengerSendResponse(messenger, response_handle, reply, |
| 48 | + reply_size); |
| 49 | + // The engine frees the response handle once |
| 50 | + // FlutterDesktopSendMessageResponse is called. |
| 51 | + response_handle = nullptr; |
| 52 | + }; |
| 53 | + |
| 54 | + const BinaryMessageHandler& message_handler = |
| 55 | + *static_cast<BinaryMessageHandler*>(user_data); |
| 56 | + |
| 57 | + message_handler(message->message, message->message_size, |
| 58 | + std::move(reply_handler)); |
| 59 | +} |
| 60 | +} // namespace |
| 61 | + |
| 62 | +BinaryMessengerImpl::BinaryMessengerImpl( |
| 63 | + FlutterDesktopMessengerRef core_messenger) |
| 64 | + : messenger_(core_messenger) {} |
| 65 | + |
| 66 | +BinaryMessengerImpl::~BinaryMessengerImpl() = default; |
| 67 | + |
| 68 | +void BinaryMessengerImpl::Send(const std::string& channel, |
| 69 | + const uint8_t* message, |
| 70 | + size_t message_size, |
| 71 | + BinaryReply reply) const { |
| 72 | + if (reply == nullptr) { |
| 73 | + FlutterDesktopMessengerSend(messenger_, channel.c_str(), message, |
| 74 | + message_size); |
| 75 | + return; |
| 76 | + } |
| 77 | + struct Captures { |
| 78 | + BinaryReply reply; |
| 79 | + }; |
| 80 | + auto captures = new Captures(); |
| 81 | + captures->reply = reply; |
| 82 | + |
| 83 | + auto message_reply = [](const uint8_t* data, size_t data_size, |
| 84 | + void* user_data) { |
| 85 | + auto captures = reinterpret_cast<Captures*>(user_data); |
| 86 | + captures->reply(data, data_size); |
| 87 | + delete captures; |
| 88 | + }; |
| 89 | + bool result = FlutterDesktopMessengerSendWithReply( |
| 90 | + messenger_, channel.c_str(), message, message_size, message_reply, |
| 91 | + captures); |
| 92 | + if (!result) { |
| 93 | + delete captures; |
| 94 | + } |
| 95 | +} |
| 96 | + |
| 97 | +void BinaryMessengerImpl::SetMessageHandler(const std::string& channel, |
| 98 | + BinaryMessageHandler handler) { |
| 99 | + if (!handler) { |
| 100 | + handlers_.erase(channel); |
| 101 | + FlutterDesktopMessengerSetCallback(messenger_, channel.c_str(), nullptr, |
| 102 | + nullptr); |
| 103 | + return; |
| 104 | + } |
| 105 | + // Save the handler, to keep it alive. |
| 106 | + handlers_[channel] = std::move(handler); |
| 107 | + BinaryMessageHandler* message_handler = &handlers_[channel]; |
| 108 | + // Set an adaptor callback that will invoke the handler. |
| 109 | + FlutterDesktopMessengerSetCallback(messenger_, channel.c_str(), |
| 110 | + ForwardToHandler, message_handler); |
| 111 | +} |
| 112 | + |
| 113 | +// ========== engine_method_result.h ========== |
| 114 | + |
| 115 | +namespace internal { |
| 116 | + |
| 117 | +ReplyManager::ReplyManager(BinaryReply reply_handler) |
| 118 | + : reply_handler_(std::move(reply_handler)) { |
| 119 | + assert(reply_handler_); |
| 120 | +} |
| 121 | + |
| 122 | +ReplyManager::~ReplyManager() { |
| 123 | + if (reply_handler_) { |
| 124 | + // Warn, rather than send a not-implemented response, since the engine may |
| 125 | + // no longer be valid at this point. |
| 126 | + std::cerr |
| 127 | + << "Warning: Failed to respond to a message. This is a memory leak." |
| 128 | + << std::endl; |
| 129 | + } |
| 130 | +} |
| 131 | + |
| 132 | +void ReplyManager::SendResponseData(const std::vector<uint8_t>* data) { |
| 133 | + if (!reply_handler_) { |
| 134 | + std::cerr |
| 135 | + << "Error: Only one of Success, Error, or NotImplemented can be " |
| 136 | + "called," |
| 137 | + << " and it can be called exactly once. Ignoring duplicate result." |
| 138 | + << std::endl; |
| 139 | + return; |
| 140 | + } |
| 141 | + |
| 142 | + const uint8_t* message = data && !data->empty() ? data->data() : nullptr; |
| 143 | + size_t message_size = data ? data->size() : 0; |
| 144 | + reply_handler_(message, message_size); |
| 145 | + reply_handler_ = nullptr; |
| 146 | +} |
| 147 | + |
| 148 | +} // namespace internal |
| 149 | + |
| 150 | +} // namespace flutter |
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