Media keys working again

daemon/device_tables.h

@@ -14,6 +14,14 @@ namespace gkeymapper::daemon {
 // A raw HID report from the vendor interface.
 using Report = std::vector<uint8_t>;
 
+// One media key: the bit it has in the media report and the Linux input code it
+// is replayed as.
+struct MediaKey {
+    uint8_t bit = 0;
+    uint16_t key = 0;    // Linux KEY_* code
+    const char* name = ""; // for the log line
+};
+
 struct DeviceProfile {
     const char* name = "";
     uint16_t vendor = 0;
@@ -22,9 +30,18 @@ struct DeviceProfile {
     int interfaceNumber = 1;
     int altSetting = 0;
 
-    // gKeyReports[i] is the press report for G(i+1).
+    // Media keys (mute / volume / play) arrive as a short report: this prefix
+    // byte followed by one bit per key, 0 when they are all released. 0 means
+    // the model reports none. This is the only path the keyboard offers for
+    // those keys, so while the daemon holds the interface the kernel does not see
+    // them at all — the daemon replays them through its virtual keyboard.
+    uint8_t mediaPrefix = 0;
+    std::vector<MediaKey> mediaKeys;
+
+    // gKeyReports[i] is the report that has the bit of G(i+1) set. Both the
+    // shared header bytes and the bit of each key are derived from these, so a
+    // new model only needs its table (see decode_gkey_state).
     std::vector<Report> gKeyReports;
-    Report releaseReport;
 
     // Some models must be told to stop mapping G-keys to F-keys first.
     bool disableBinding = false;
@@ -36,11 +53,24 @@ const std::vector<DeviceProfile>& profiles();
 // Matching profile for vendor/product, or nullptr.
 const DeviceProfile* find_profile(uint16_t vendor, uint16_t product);
 
-// Index of the G key (0..N-1) for a report, or -1 if it is not a known press.
-int match_gkey(const DeviceProfile& profile, const uint8_t* data, int length);
+// Decodes a macro-key report into the keys it reports as pressed: bit 0 = G1 ..
+// bit 8 = G9. Returns false for every other report — the media keys have their
+// own decoder below, and memory keys, LED and command acknowledgements are
+// ignored on purpose.
+//
+// The report carries the state of all G keys, not a single key: one report with
+// several bits set means a chord, and "no bit set" is the release. The caller
+// compares consecutive states, which makes a held key (repeating report) fire
+// once and a chord fire every key it contains.
+bool decode_gkey_state(const DeviceProfile& profile, const uint8_t* data, int length,
+                       uint32_t& pressed);
 
-// True if the report is the "all macro keys released" report.
-bool is_release_report(const DeviceProfile& profile, const uint8_t* data, int length);
+// Decodes a media-key report into its bits (bit set = key held), using the bit
+// table of the profile. `bits` is 0 for the release report, which is a valid
+// media report. Returns false for every other report, in particular for the
+// macro-key reports.
+bool decode_media_key(const DeviceProfile& profile, const uint8_t* data, int length,
+                      uint32_t& bits);
 
 } // namespace gkeymapper::daemon