Better wrap our Gio.Settings in our Settings class

This allows us for checking if keys on the schema exist so we don't fail
with newer gsetwacom running on older gnome versions where some keys
may not exist.

Fixes: 5fe1b32 ("Support stylus keybindings")
Fixes: 99ca77f ("Add support for pressure ranges")

src/gsetwacom/__init__.py

@@ -28,6 +28,36 @@ class Settings:
     path: str
     settings: Gio.Settings
 
+    def set_value(self, key, value):
+        if self.has_key(key):
+            self.settings.set_value(key, value)
+        else:
+            click.secho(f"WARNING: {key} does not exist in the schema, ignoring")
+
+    def set_enum(self, key, value):
+        if self.has_key(key):
+            self.settings.set_enum(key, value)
+        else:
+            click.secho(f"WARNING: {key} does not exist in the schema, ignoring")
+
+    def set_string(self, key, value):
+        if self.has_key(key):
+            self.settings.set_string(key, value)
+        else:
+            click.secho(f"WARNING: {key} does not exist in the schema, ignoring")
+
+    def set_boolean(self, key, value):
+        if self.has_key(key):
+            self.settings.set_boolean(key, value)
+        else:
+            click.secho(f"WARNING: {key} does not exist in the schema, ignoring")
+
+    def has_key(self, key) -> bool:
+        return self.settings.props.settings_schema.has_key(key)
+
+    def get_value(self, key):
+        return self.settings.get_value(key)
+
 
 @click.group()
 @click.option("-v", "--verbose", count=True, help="increase verbosity")
@@ -134,10 +164,10 @@ def tablet_show(ctx):
     """
     Show the current configuraton of the given tablet DEVICE.
     """
-    settings = ctx.obj.settings
+    settings = ctx.obj
     keys = ("area", "keep-aspect", "left-handed", "mapping", "output")
     click.echo("settings:")
-    for key in keys:
+    for key in filter(lambda k: settings.has_key(k), keys):
         click.echo(f"  {key}: {settings.get_value(key)}")
 
 
@@ -148,7 +178,7 @@ def tablet_set_left_handed(ctx, left_handed: bool):
     """
     Change the left-handed configuration of this device
     """
-    settings = ctx.obj.settings
+    settings = ctx.obj
     settings.set_boolean("left-handed", left_handed)
 
 
@@ -162,7 +192,7 @@ def tablet_set_keep_aspect(ctx, keep_aspect_ratio: bool):
     A device with keep-aspect enabled will reduce its available area
     to match the aspect ratio of the monitor it is mapped to.
     """
-    settings = ctx.obj.settings
+    settings = ctx.obj
     settings.set_boolean("keep-aspect", keep_aspect_ratio)
 
 
@@ -173,7 +203,7 @@ def tablet_set_absolute(ctx, absolute: bool):
     """
     Change the left-handed configuration of this device
     """
-    settings = ctx.obj.settings
+    settings = ctx.obj
     settings.set_boolean("absolute", "absolute" if absolute else "relative")
 
 
@@ -187,7 +217,7 @@ def tablet_set_area(ctx, x1: float, y1: float, x2: float, y2: float):
     """
     Change the area the tablet is mapped to. All input parameters are percentages.
     """
-    settings = ctx.obj.settings
+    settings = ctx.obj
     settings.set_value("area", GLib.Variant("ad", [x1, y1, x2, y2]))
 
 
@@ -252,7 +282,7 @@ class Monitor:
         logger.info("Monitor on %s vendor '%s' product '%s' serial '%s'", *asdict(monitor).values())
         if any(args[key] is not None and args[key] != getattr(monitor, key) for key in args):
             continue
-        settings = ctx.obj.settings
+        settings = ctx.obj
         settings.set_value(
             "output",
             GLib.Variant(
@@ -388,7 +418,7 @@ def stylus_show(ctx):
     """
     Show the current configuraton of the given STYLUS.
     """
-    settings = ctx.obj.settings
+    settings = ctx.obj
     keys = (
         "pressure-curve",
         "eraser-pressure-curve",
@@ -402,7 +432,7 @@ def stylus_show(ctx):
         "tertiary-button-keybinding",
     )
     click.echo("settings:")
-    for key in keys:
+    for key in filter(lambda k: settings.has_key(k), keys):
         click.echo(f"  {key}: {settings.get_value(key)}")
 
 
@@ -420,7 +450,7 @@ def stylus_set_pressure_curve(ctx, eraser: bool, x1: int, y1: int, x2: int, y2:
     The given arguments must be in the range [0, 100] and describe the two points BC
     of a bezier curve ABCD where A = (0, 0) and D = (100, 100).
     """
-    settings = ctx.obj.settings
+    settings = ctx.obj
     key = "eraser-pressure-curve" if eraser else "pressure-curve"
     settings.set_value(key, GLib.Variant("ai", [x1, y1, x2, y2]))
 
@@ -436,7 +466,7 @@ def stylus_set_pressure_range(ctx, eraser: bool, minimum: int, maximum: int):
 
     The given arguments must be in the range [0, 100].
     """
-    settings = ctx.obj.settings
+    settings = ctx.obj
     key = "eraser-pressure-range" if eraser else "pressure-range"
     settings.set_value(key, GLib.Variant("ai", [minimum, maximum]))
 
@@ -465,7 +495,7 @@ def stylus_set_button_action(ctx, button: str, action: str, keybinding: str | No
             msg = "Keybinding is only valid for action keybinding"
             raise click.UsageError(msg)
 
-    settings = ctx.obj.settings
+    settings = ctx.obj
 
     button_prefix = {
         "primary": "button",