megapixels-next: make it the default camera

hosts/common/programs/megapixels-next.nix

@@ -17,8 +17,11 @@
       postInstall = (base.postInstall or "") + ''
         mv $out/bin/megapixels $out/bin/megapixels-next
 
-        rm $out/share/applications/me.gapixels.Megapixels.desktop
+        substituteInPlace $out/share/applications/me.gapixels.Megapixels.desktop \
+          --replace "megapixels" "megapixels-next"
       '';
     });
+
+    env.CAMERA = "me.gapixels.Megapixels.desktop";
   };
 }

hosts/common/programs/megapixels.nix

@@ -50,5 +50,8 @@
     # sandbox.keepPidsAndProc = true;
 
     suggestedPrograms = [ "dconf" ];  #< not sure if necessary
+
+    mime.priority = 200;  #< fallback
+    env.CAMERA = "org.postmarketos.Megapixels.desktop";
   };
 }

hosts/common/programs/sane-input-handler/sane-input-handler

@@ -58,6 +58,7 @@
 # increments to use for volume adjustment (in %)
 VOL_INCR=5
 KEYBOARD="${KEYBOARD:-wvkbd-mobintl}"
+CAMERA="${CAMERA:-org.postmarketos.Megapixels.desktop}"
 
 action="$1"
 
@@ -228,7 +229,7 @@ dispatchOn() {
       ;;
     "power_and_voldown")
       # power (hold) -> voldown: open camera
-      handleWith sane-open --auto-keyboard --application org.postmarketos.Megapixels.desktop
+      handleWith sane-open --auto-keyboard --application "$CAMERA"
       ;;
     "power_then_volup")
       # power (tap) -> volup: rotate CCW