| 1 | // =============================================================== // |
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| 2 | // // |
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| 3 | // File : FileWatch.h // |
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| 4 | // Purpose : Watch awar pointing to file AND file itself // |
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| 5 | // // |
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| 6 | // Coded by Ralf Westram (coder@reallysoft.de) in October 2017 // |
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| 7 | // http://www.arb-home.de/ // |
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| 8 | // // |
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| 9 | // =============================================================== // |
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| 10 | |
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| 11 | #ifndef FILEWATCH_H |
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| 12 | #define FILEWATCH_H |
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| 13 | |
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| 14 | #ifndef AW_AWAR_HXX |
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| 15 | #include <aw_awar.hxx> |
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| 16 | #endif |
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| 17 | #ifndef AW_ROOT_HXX |
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| 18 | #include <aw_root.hxx> |
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| 19 | #endif |
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| 20 | #ifndef AW_INOTIFY_HXX |
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| 21 | #include <aw_inotify.hxx> |
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| 22 | #endif |
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| 23 | #ifndef ARB_FILE_H |
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| 24 | #include <arb_file.h> |
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| 25 | #endif |
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| 26 | |
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| 27 | /* Binds user-callback to an awar which contains a filename (full-path; e.g. from File_selection) |
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| 28 | * - the user-callback will be called whenever the awar triggers |
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| 29 | * - the awar will automatically change when |
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| 30 | * - it points to a file and the file gets modified (awar gets touched) |
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| 31 | * - the file is deleted (awar changes to "") |
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| 32 | * - the file is re-created (if awar is "" -> awar points to file again) |
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| 33 | */ |
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| 34 | |
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| 35 | class FileWatch : virtual Noncopyable { |
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| 36 | AW_awar *awar_selfile; // contains name of file (or sth invalid like "") |
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| 37 | SmartCharPtr watched_file; // if set -> currently watched file |
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| 38 | FileChangedCallback wf_cb; // used to watch file changes |
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| 39 | FileChangedCallback user_cb; // called if awar or (pointed-to) file changes |
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| 40 | // Warning: be aware that callbacks may be called with empty name (""), |
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| 41 | // depending on where awar is used! |
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| 42 | |
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| 43 | void file_modified_handler(const char *file, ChangeReason reason) const { |
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| 44 | // - corrects "selected file" in response to filesystem changes (de- and re-select) |
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| 45 | // - triggers awar callback if file gets modified |
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| 46 | |
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| 47 | switch (reason) { |
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| 48 | case CR_CREATED: |
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| 49 | case CR_MODIFIED: |
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| 50 | if (awar_selfile->read_char_pntr()[0]) { // awar has content (do not overwrite) |
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| 51 | awar_selfile->touch(); |
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| 52 | } |
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| 53 | else if (GB_is_regularfile(file)) { |
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| 54 | awar_selfile->write_string(file); |
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| 55 | } |
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| 56 | break; |
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| 57 | case CR_DELETED: |
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| 58 | aw_assert(!GB_is_regularfile(file)); |
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| 59 | awar_selfile->write_string(""); |
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| 60 | break; |
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| 61 | } |
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| 62 | |
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| 63 | } |
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| 64 | |
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| 65 | void remove_inotification() { |
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| 66 | if (watched_file.isSet()) { |
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| 67 | AW_remove_inotification(&*watched_file, wf_cb); |
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| 68 | watched_file.setNull(); |
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| 69 | } |
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| 70 | } |
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| 71 | |
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| 72 | void awar_modified_handler() { |
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| 73 | SmartCharPtr file(awar_selfile->read_string()); |
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| 74 | |
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| 75 | bool points_to_file = GB_is_regularfile(&*file); |
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| 76 | bool need_change_watch = |
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| 77 | points_to_file |
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| 78 | ? (watched_file.isNull() || strcmp(&*watched_file, &*file) != 0) |
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| 79 | : watched_file.isSet(); |
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| 80 | |
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| 81 | if (need_change_watch) { |
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| 82 | remove_inotification(); |
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| 83 | if (points_to_file) { |
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| 84 | watched_file = file; |
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| 85 | AW_add_inotification(&*watched_file, wf_cb); |
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| 86 | } |
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| 87 | } |
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| 88 | |
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| 89 | user_cb(&*file, CR_MODIFIED); |
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| 90 | } |
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| 91 | |
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| 92 | // callback-wrappers |
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| 93 | static void file_modified_wrapper(const char *file, ChangeReason reason, FileWatch *watch) { watch->file_modified_handler(file, reason); } |
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| 94 | static void awar_modified_wrapper(AW_root*, FileWatch *watch) { watch->awar_modified_handler(); } |
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| 95 | |
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| 96 | public: |
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| 97 | |
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| 98 | FileWatch(const char *sel_file_awar, const FileChangedCallback& file_changed_cb) : |
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| 99 | awar_selfile(AW_root::SINGLETON->awar(sel_file_awar)), |
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| 100 | wf_cb(makeFileChangedCallback(file_modified_wrapper, this)), |
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| 101 | user_cb(file_changed_cb) |
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| 102 | { |
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| 103 | awar_selfile->add_callback(makeRootCallback(awar_modified_wrapper, this)); |
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| 104 | } |
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| 105 | |
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| 106 | ~FileWatch() { |
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| 107 | awar_selfile->remove_callback(makeRootCallback(awar_modified_wrapper, this)); |
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| 108 | remove_inotification(); |
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| 109 | } |
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| 110 | }; |
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| 111 | |
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| 112 | #else |
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| 113 | #error FileWatch.h included twice |
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| 114 | #endif // FILEWATCH_H |
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