实验了一个比较奇特的东西，在PPAPI插件里创建一个本地窗口，叠加在插件在网页的位置上。 CEF3默认是多进程架构，PPAPI插件在一个单独进程里跑，这个进程没启动Windows的消息循环，所以，要创建插件的话，得自己搞一个消息循环。另外浏览器窗口属于别的进程，怎么把创建出来的窗口成为浏览器窗口的子窗口，也是个问题。这个第一个要解决的问题。 CEF3还支持单进程运行，Browser、Render、Plugin合一，此时创建本地窗口又和多进程不同。这是第二个问题。 第三个问题是，如何把窗口定位到网页的插件区域。 琢磨了下，都解决了。 > foruok原创，如需转载请关注foruok的微信订阅号“程序视界”联系foruok。 # 效果 先看看效果图。先是跨进程的：  灰色区域那里是我创建的本地窗口，上面有一行字。 再看同一进程的：  注意文字的变化。 # 代码 Talk is cheap，show me the code： ~~~ /* Copyright (c) 2012 The Chromium Authors. All rights reserved. * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. * 2016-1-13, edited by foruok. * 如需转载，请关注微信订阅号“程序视界”，回复foruok获取其联系方式 * */ #include <stdint.h> #include <stdlib.h> #include <string.h> #include <Windows.h> #include <tchar.h> #include "ppapi/c/pp_completion_callback.h" #include "ppapi/c/pp_errors.h" #include "ppapi/c/pp_instance.h" #include "ppapi/c/pp_module.h" #include "ppapi/c/pp_rect.h" #include "ppapi/c/pp_var.h" #include "ppapi/c/ppb.h" #include "ppapi/c/ppb_core.h" #include "ppapi/c/ppb_graphics_2d.h" #include "ppapi/c/ppb_image_data.h" #include "ppapi/c/ppb_instance.h" #include "ppapi/c/ppb_view.h" #include "ppapi/c/ppp.h" #include "ppapi/c/ppp_instance.h" #include "ppapi/c/ppb_input_event.h" #include "ppapi/c/ppp_input_event.h" PPB_GetInterface g_get_browser_interface = NULL; const PPB_Core* g_core_interface; const PPB_Graphics2D* g_graphics_2d_interface; const PPB_ImageData* g_image_data_interface; const PPB_Instance* g_instance_interface; const PPB_View* g_view_interface; const PPB_InputEvent *g_input_interface; const PPB_MouseInputEvent *g_mouse_interface; /******foruok: create native window begin******/ static HWND g_child_window = NULL; struct CreateChildWinParam { struct PP_Rect r; HWND hWndParent; }; HANDLE g_hThread = NULL; DWORD g_dwThreadId = 0; BOOL g_bInProcess = 0; static LRESULT CALLBACK VideoWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam ) { PAINTSTRUCT ps; HDC hdc; RECT r; TCHAR textIn[] = _T("Child Window(in-process)"); TCHAR text[] = _T("Child Window(out-process)"); switch (uMsg) { case WM_PAINT: GetClientRect(hwnd, &r); hdc = BeginPaint(hwnd, &ps); SetTextColor(hdc, RGB(0, 200, 0)); FillRect(hdc, &r, GetStockObject(GRAY_BRUSH)); if (g_bInProcess) { TextOut(hdc, 10, 50, textIn, ARRAYSIZE(textIn) - 1); } else { TextOut(hdc, 10, 50, text, ARRAYSIZE(text) - 1); } EndPaint(hwnd, &ps); return 0; } return DefWindowProc(hwnd, uMsg, wParam, lParam); } static void RegisterVideoWindowClass() { WNDCLASSEX wcex = { /* cbSize = */ sizeof(WNDCLASSEX), /* style = */ CS_HREDRAW | CS_VREDRAW, /* lpfnWndProc = */ VideoWindowProc, /* cbClsExtra = */ 0, /* cbWndExtra = */ 0, /* hInstance = */ GetModuleHandle(NULL), /* hIcon = */ NULL, /* hCursor = */ LoadCursor(NULL, IDC_ARROW), /* hbrBackground = */ 0, /* lpszMenuName = */ NULL, /* lpszClassName = */ _T("_ChildWindowClass"), /* hIconSm = */ NULL, }; RegisterClassEx(&wcex); } DWORD WINAPI ThreadProc(LPVOID lpParam) { MSG msg; struct CreateChildWinParam *para = (struct CreateChildWinParam *)lpParam; TCHAR szLog[256] = { 0 }; g_child_window = CreateWindowEx(0, _T("_ChildWindowClass"), _T("ChildWindow"), para->hWndParent == NULL ? (WS_OVERLAPPEDWINDOW | WS_VISIBLE) : (WS_CHILD | WS_VISIBLE | WS_DISABLED), para->r.point.x, para->r.point.y, para->r.size.width, para->r.size.height, para->hWndParent, NULL, GetModuleHandle(NULL), NULL); _stprintf_s(szLog, 256, _T("create child window(standalone msg loop) at (%d, %d) child = 0x%08x\r\n"), para->r.point.x, para->r.point.y, g_child_window); OutputDebugString(szLog); BOOL fGotMessage; while ((fGotMessage = GetMessage(&msg, (HWND)NULL, 0, 0)) != 0 && fGotMessage != -1) { TranslateMessage(&msg); if (msg.message == WM_USER && msg.hwnd == NULL) { OutputDebugString(_T("child window message loop quit\r\n")); g_dwThreadId = 0; g_hThread = NULL; g_child_window = NULL; return 0; } DispatchMessage(&msg); } return msg.wParam; } void CreateChildWindowOnMainThread(void *param, int32_t result) { struct CreateChildWinParam *p = (struct CreateChildWinParam *)param; g_child_window = CreateWindowEx(0, _T("_ChildWindowClass"), _T("ChildWindow"), WS_CHILD | WS_VISIBLE, p->r.point.x, p->r.point.y, p->r.size.width, p->r.size.height, p->hWndParent, NULL, GetModuleHandle(NULL), NULL); TCHAR szLog[256] = { 0 }; _stprintf_s(szLog, 256, _T("create child window(in-process) at (%d, %d) child = 0x%08x\r\n"), p->r.point.x, p->r.point.y, g_child_window); OutputDebugString(szLog); ShowWindow(g_child_window, SW_SHOW); UpdateWindow(g_child_window); } void CreateChildWindow(struct PP_Rect *r) { HWND hwnd = FindWindowEx(NULL, NULL, _T("CefBrowserWindow"), NULL); HWND hwndWeb = FindWindowEx(hwnd, NULL, _T("Chrome_WidgetWin_0"), NULL);; /*if (hwndWeb) { hwndWeb = FindWindowEx(hwndWeb, NULL, _T("Chrome_RenderWidgetHostHWND"), NULL); //web contents }*/ if (hwndWeb != NULL)OutputDebugString(_T("Got Chrome_RenderWidgetHostHWND\r\n")); DWORD pluginPid = GetCurrentProcessId(); DWORD browserPid = 0; GetWindowThreadProcessId(hwnd, &browserPid); TCHAR szLog[256] = { 0 }; _stprintf_s(szLog, 256, _T("Browser pid - %d, plugin pid - %d, brower hwnd - 0x%08x, webpage hwnd - 0x%08x\r\n"), browserPid, pluginPid, hwnd, hwndWeb); OutputDebugString(szLog); struct CreateChildWinParam *para = (struct PP_Rect *)malloc(sizeof(struct CreateChildWinParam)); para->r = *r; para->hWndParent = hwndWeb; if (browserPid == pluginPid) { g_bInProcess = TRUE; g_core_interface->CallOnMainThread(0, PP_MakeCompletionCallback(CreateChildWindowOnMainThread, para), 0); } else { g_bInProcess = FALSE; g_hThread = CreateThread(NULL, 0, ThreadProc, para, 0, &g_dwThreadId); if (g_hThread != NULL) { OutputDebugString(_T("Launch child window thread.\r\n")); } else { OutputDebugString(_T("Launch child window thread FAILED!\r\n")); } } } /* PPP_Instance implementation -----------------------------------------------*/ struct InstanceInfo { PP_Instance pp_instance; struct PP_Size last_size; PP_Resource graphics; struct InstanceInfo* next; }; /** Linked list of all live instances. */ struct InstanceInfo* all_instances = NULL; /** Returns a refed resource corresponding to the created graphics 2d. */ PP_Resource MakeAndBindGraphics2D(PP_Instance instance, const struct PP_Size* size) { PP_Resource graphics; graphics = g_graphics_2d_interface->Create(instance, size, PP_FALSE); if (!graphics) return 0; if (!g_instance_interface->BindGraphics(instance, graphics)) { g_core_interface->ReleaseResource(graphics); return 0; } return graphics; } void FlushCompletionCallback(void* user_data, int32_t result) { /* Don't need to do anything here. */ } unsigned int g_colors[4] = { 0xFF888888, 0xFFFF00FF, 0xFF00FFFF, 0xFFEA00FF }; unsigned int g_color_index = 0; void Repaint(struct InstanceInfo* instance, const struct PP_Size* size) { PP_Resource image; struct PP_ImageDataDesc image_desc; uint32_t* image_data; int num_words, i; /* Ensure the graphics 2d is ready. */ if (!instance->graphics) { instance->graphics = MakeAndBindGraphics2D(instance->pp_instance, size); if (!instance->graphics) return; } /* Create image data to paint into. */ image = g_image_data_interface->Create( instance->pp_instance, PP_IMAGEDATAFORMAT_BGRA_PREMUL, size, PP_TRUE); if (!image) return; g_image_data_interface->Describe(image, &image_desc); /* Fill the image with blue. */ image_data = (uint32_t*)g_image_data_interface->Map(image); if (!image_data) { g_core_interface->ReleaseResource(image); return; } num_words = image_desc.stride * size->height / 4; g_color_index++; if (g_color_index >= sizeof(g_colors) / sizeof(g_colors[0])) g_color_index = 0; for (i = 0; i < num_words; i++) image_data[i] = g_colors[g_color_index]; /* Paint image to graphics 2d. */ g_graphics_2d_interface->ReplaceContents(instance->graphics, image); g_graphics_2d_interface->Flush(instance->graphics, PP_MakeCompletionCallback(&FlushCompletionCallback, NULL)); g_core_interface->ReleaseResource(image); } /** Returns the info for the given instance, or NULL if it's not found. */ struct InstanceInfo* FindInstance(PP_Instance instance) { struct InstanceInfo* cur = all_instances; while (cur) { if (cur->pp_instance == instance) return cur; cur = cur->next; } return NULL; } PP_Bool Instance_DidCreate(PP_Instance instance, uint32_t argc, const char* argn[], const char* argv[]) { struct InstanceInfo* info = (struct InstanceInfo*)malloc(sizeof(struct InstanceInfo)); info->pp_instance = instance; info->last_size.width = 0; info->last_size.height = 0; info->graphics = 0; /* Insert into linked list of live instances. */ info->next = all_instances; all_instances = info; g_input_interface->RequestInputEvents(instance, PP_INPUTEVENT_CLASS_MOUSE); g_input_interface->RequestFilteringInputEvents(instance, PP_INPUTEVENT_CLASS_MOUSE); OutputDebugString(_T("Instance_DidCreate\r\n")); return PP_TRUE; } void Instance_DidDestroy(PP_Instance instance) { /* Find the matching item in the linked list, delete it, and patch the * links. */ struct InstanceInfo** prev_ptr = &all_instances; struct InstanceInfo* cur = all_instances; while (cur) { if (instance == cur->pp_instance) { *prev_ptr = cur->next; g_core_interface->ReleaseResource(cur->graphics); free(cur); return; } prev_ptr = &cur->next; cur = cur->next; } /**foruok: close native window**/ if(g_child_window != NULL)SendMessage(g_child_window, WM_CLOSE, 0, 0); if (g_dwThreadId != 0) { OutputDebugString(_T("Plugin was destroyed, tell child window close and thread exit\r\n")); PostThreadMessage(g_dwThreadId, WM_USER, 0, 0); } } void Instance_DidChangeView(PP_Instance pp_instance, PP_Resource view) { struct PP_Rect position; struct InstanceInfo* info = FindInstance(pp_instance); if (!info) return; if (g_view_interface->GetRect(view, &position) == PP_FALSE) return; if (info->last_size.width != position.size.width || info->last_size.height != position.size.height) { /* Got a resize, repaint the plugin. */ Repaint(info, &position.size); info->last_size.width = position.size.width; info->last_size.height = position.size.height; /**foruok: call create window**/ if (g_child_window == NULL) { CreateChildWindow(&position); } } OutputDebugString(_T("Instance_DidChangeView\r\n")); } void Instance_DidChangeFocus(PP_Instance pp_instance, PP_Bool has_focus) { } PP_Bool Instance_HandleDocumentLoad(PP_Instance pp_instance, PP_Resource pp_url_loader) { return PP_FALSE; } static PPP_Instance instance_interface = { &Instance_DidCreate, &Instance_DidDestroy, &Instance_DidChangeView, &Instance_DidChangeFocus, &Instance_HandleDocumentLoad }; PP_Bool InputEvent_HandleInputEvent(PP_Instance instance, PP_Resource input_event) { struct PP_Point pt; TCHAR szLog[512] = { 0 }; switch (g_input_interface->GetType(input_event)) { case PP_INPUTEVENT_TYPE_MOUSEDOWN: pt = g_mouse_interface->GetPosition(input_event); _stprintf_s(szLog, 512, _T("InputEvent_HandleInputEvent, mouse down at [%d, %d]\r\n"), pt.x, pt.y); OutputDebugString(szLog); break; /* case PP_INPUTEVENT_TYPE_MOUSEUP: OutputDebugString(_T("InputEvent_HandleInputEvent, mouse up\r\n")); break; case PP_INPUTEVENT_TYPE_MOUSEMOVE: OutputDebugString(_T("InputEvent_HandleInputEvent, mouse move\r\n")); break; case PP_INPUTEVENT_TYPE_MOUSEENTER: OutputDebugString(_T("InputEvent_HandleInputEvent, mouse enter\r\n")); break; case PP_INPUTEVENT_TYPE_MOUSELEAVE: OutputDebugString(_T("InputEvent_HandleInputEvent, mouse leave\r\n")); break; */ default: return PP_FALSE; } struct InstanceInfo* info = FindInstance(instance); if (info && info->last_size.width > 0) { Repaint(info, &info->last_size); } return PP_TRUE; } static PPP_InputEvent input_interface = { &InputEvent_HandleInputEvent }; /* Global entrypoints --------------------------------------------------------*/ PP_EXPORT int32_t PPP_InitializeModule(PP_Module module, PPB_GetInterface get_browser_interface) { /**foruok: register window class**/ RegisterVideoWindowClass(); g_get_browser_interface = get_browser_interface; g_core_interface = (const PPB_Core*) get_browser_interface(PPB_CORE_INTERFACE); g_instance_interface = (const PPB_Instance*) get_browser_interface(PPB_INSTANCE_INTERFACE); g_image_data_interface = (const PPB_ImageData*) get_browser_interface(PPB_IMAGEDATA_INTERFACE); g_graphics_2d_interface = (const PPB_Graphics2D*) get_browser_interface(PPB_GRAPHICS_2D_INTERFACE); g_view_interface = (const PPB_View*) get_browser_interface(PPB_VIEW_INTERFACE); g_input_interface = (const PPB_InputEvent*)get_browser_interface(PPB_INPUT_EVENT_INTERFACE); g_mouse_interface = (const PPB_MouseInputEvent*)get_browser_interface(PPB_MOUSE_INPUT_EVENT_INTERFACE); if (!g_core_interface || !g_instance_interface || !g_image_data_interface || !g_graphics_2d_interface || !g_view_interface || !g_input_interface || !g_mouse_interface) return -1; OutputDebugString(_T("PPP_InitializeModule\r\n")); return PP_OK; } PP_EXPORT void PPP_ShutdownModule() { } PP_EXPORT const void* PPP_GetInterface(const char* interface_name) { if (strcmp(interface_name, PPP_INSTANCE_INTERFACE) == 0) { OutputDebugString(_T("PPP_GetInterface, instance_interface\r\n")); return &instance_interface; } else if (strcmp(interface_name, PPP_INPUT_EVENT_INTERFACE) == 0) { OutputDebugString(_T("PPP_GetInterface, input_interface\r\n")); return &input_interface; } return NULL; } ~~~ 工程和原来差不多，不说了。 代码基于[**PPAPI插件的绘图与输入事件处理**](http://blog.csdn.net/foruok/article/details/50499813)改造，添加的部分，在注释处加入了foruok标签，搜索即可查看。下面说明几点。 ### 本地窗口的创建 CreateChildWindow()函数是创建本地窗口的入口函数，它利用进程id，判断了插件进程与浏览器进程是否同一进程。 如果是同一进程，通过调用PPB_Core的CallOnMainThread方法，在主线程执行CreateChildWindowOnMainThread来创建子窗口。 如果不是同一进程，就创建一个线程，在线程里创建窗口并启动了消息循环。注意，Windows下窗口的父子关注，支持跨进程，所以调用CreateWindowEx时只要指定父窗口句柄即可。 ### 窗口定位 DidChangeView方法之前在[**理解PPAPI的设计**](http://blog.csdn.net/foruok/article/details/50486788)里提到过，当插件和浏览器的视图关联起来或者视图发生变化时，DidChangeView方法会被调用。这次我们就在这里创建窗口。窗口的位置，可以通过PPB_View接口的GetRect()方法获取到。这个位置就是我们要创建的本地窗口的位置，传递给CreateWindowEx方法即可。 好啦，新的示例主要就这些内容了，处理输入事件的流程应该也清楚了。 这次实验的东西比较奇特，不走寻常路，仅仅是为了兼容老代码…… 相关文章参考： - [**CEF Windows开发环境搭建**](http://blog.csdn.net/foruok/article/details/50468642) - [**CEF加载PPAPI插件**](http://blog.csdn.net/foruok/article/details/50485448) - [**VS2013编译最简单的PPAPI插件**](http://blog.csdn.net/foruok/article/details/50485461) - [**理解PPAPI的设计**](http://blog.csdn.net/foruok/article/details/50486788) - [**PPAPI插件与浏览器的交互过程**](http://blog.csdn.net/foruok/article/details/50494061) - [**Windows下从源码编译CEF**](http://blog.csdn.net/foruok/article/details/50498740) - [**编译PPAPI的media_stream_video示例**](http://blog.csdn.net/foruok/article/details/50498873) - [**PPAPI插件的绘图与输入事件处理**](http://blog.csdn.net/foruok/article/details/50499813)