\nToday’s Little Program plays a little sound every time the foreground\nwindow changes.\nOne of my colleagues wondered if such a program was possible,\n“so that I stop accidentally typing the second halves of paragraphs\ninto windows that pop up and steal focus.”\nIt’s not clear whether this program will actually solve the bigger\nproblem,\nbut it was fun writing the program,\nand maybe you can use it for something.\n<\/p>\n
\n#define STRICT\n#include <windows.h>\n#include <mmsystem.h>\nvoid CALLBACK WinEventProc(\n HWINEVENTHOOK hWinEventHook,\n DWORD event,\n HWND hwnd,\n LONG idObject,\n LONG idChild,\n DWORD dwEventThread,\n DWORD dwmsEventTime\n)\n{\n if (hwnd &&\n idObject == OBJID_WINDOW &&\n idChild == CHILDID_SELF &&\n event == EVENT_SYSTEM_FOREGROUND) {\n PlaySound(TEXT(\"C:\\\\Windows\\\\Media\\\\Speech Misrecognition.wav\"),\n NULL, SND_FILENAME | SND_ASYNC);\n }\n}\nint WINAPI WinMain(HINSTANCE hinst, HINSTANCE hinstPrev,\n LPSTR lpCmdLine, int nShowCmd)\n{\n HWINEVENTHOOK hWinEventHook = SetWinEventHook(\n EVENT_SYSTEM_FOREGROUND, EVENT_SYSTEM_FOREGROUND,\n NULL, WinEventProc, 0, 0,\n WINEVENT_OUTOFCONTEXT | WINEVENT_SKIPOWNPROCESS);\n MSG msg;\n while (GetMessage(&msg, NULL, 0, 0)) {\n TranslateMessage(&msg);\n DispatchMessage(&msg);\n }\n if (hWinEventHook) UnhookWinEvent(hWinEventHook);\n return 0;\n}\n<\/pre>\n\nThis program installs an accessibility hook that\nlistens for changes to the system foreground.\nAnd when it happens, we play a little sound.\n<\/p>\n
\nI chose the Windows 7 Speech Misrecognition sound\nbecause it’s relatively unobtrusive.\nAnd the sound is played asynchronously so as not to\nblock the message pump thread.\nIt also has as a pleasant side-effect that if\nthe foreground changes many times rapidly,\nthe new sound will interrupt the old one rather than\nqueueing up behind it.\n<\/p>\n
\nNote that there is no way to exit this program short of\nkilling it in Task Manager.\nThat’s why it’s a Little Program rather than a real program.<\/p>\n","protected":false},"excerpt":{"rendered":"
Today’s Little Program plays a little sound every time the foreground window changes. One of my colleagues wondered if such a program was possible, “so that I stop accidentally typing the second halves of paragraphs into windows that pop up and steal focus.” It’s not clear whether this program will actually solve the bigger problem, […]<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[25],"class_list":["post-3083","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-code"],"acf":[],"blog_post_summary":"
Today’s Little Program plays a little sound every time the foreground window changes. One of my colleagues wondered if such a program was possible, “so that I stop accidentally typing the second halves of paragraphs into windows that pop up and steal focus.” It’s not clear whether this program will actually solve the bigger problem, […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/3083","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=3083"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/3083\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=3083"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=3083"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=3083"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}