Implement controlPressed and shiftPressed

ts/editor/Tag.svelte

@@ -7,6 +7,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     import { nightModeKey } from "components/contextKeys";
     import Badge from "components/Badge.svelte";
     import { deleteIcon } from "./icons";
+    import { controlPressed, shiftPressed } from "lib/keys";
 
     export let name: string;
 
@@ -23,39 +24,35 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
         setTimeout(() => (flashing = false), 300);
     }
 
-    let showDelete = true;
+    let hideDelete = false;
 
-    function hideDeleteOnCtrlShfit(event: MouseEvent) {
-        showDelete = !event.ctrlKey && !event.shiftKey;
+    function setDeleteIcon(event: KeyboardEvent | MouseEvent) {
+        hideDelete = controlPressed(event) || shiftPressed(event);
     }
 
-    function showDeleteOnLeave() {
-        showDelete = true;
-    }
-
-    function toggleDelete() {
-        // TODO
+    function showDeleteIcon() {
+        hideDelete = true;
     }
 
     const nightMode = getContext<boolean>(nightModeKey);
 </script>
 
+<svelte:body on:keydown={setDeleteIcon} on:keyup={setDeleteIcon} />
+
 <button
-    class="btn d-inline-flex align-items-center text-nowrap rounded ps-2 pe-1 me-1"
+    class="tag btn d-inline-flex align-items-center text-nowrap rounded ps-2 pe-1 me-1"
     class:flashing
+    class:hide-delete={hideDelete}
     class:btn-day={!nightMode}
     class:btn-night={nightMode}
     tabindex="-1"
-    on:mousemove={hideDeleteOnCtrlShfit}
-    on:mouseleave={showDeleteOnLeave}
-    on:keydown={toggleDelete}
-    on:keyup={toggleDelete}
+    on:mouseleave={showDeleteIcon}
+    on:mousemove={setDeleteIcon}
     on:click
 >
     <span>{name}</span>
-    <Badge
-        class={`delete-icon rounded ms-1 mt-1${showDelete ? "" : " opacity-0"}`}
-        on:click={deleteTag}>{@html deleteIcon}</Badge
+    <Badge class="delete-icon rounded ms-1 mt-1" on:click={deleteTag}
+        >{@html deleteIcon}</Badge
     >
 </button>
 
@@ -85,15 +82,16 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
         &.flashing {
             animation: flash 0.3s linear;
         }
+
+        &.hide-delete:hover :global(.delete-icon) {
+            opacity: 0;
+        }
     }
 
-    @include button.btn-day($with-active: false);
-    @include button.btn-night($with-active: false);
-
+    :global(.delete-icon > svg:hover) {
         $white-translucent: rgba(255 255 255 / 0.5);
         $dark-translucent: rgba(0 0 0 / 0.2);
 
-    :global(.delete-icon > svg:hover) {
         .btn-day & {
             background-color: $dark-translucent;
         }
@@ -102,4 +100,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
             background-color: $white-translucent;
         }
     }
+
+    @include button.btn-day($with-active: false);
+    @include button.btn-night($with-active: false);
 </style>

ts/lib/keys.ts

@@ -4,15 +4,17 @@
 import * as tr from "./i18n";
 import { isApplePlatform } from "./platform";
 
+// those are the modifiers that Anki works with
 export type Modifier = "Control" | "Alt" | "Shift" | "Meta";
-
-// how modifiers are mapped
 const allModifiers: Modifier[] = ["Control", "Alt", "Shift", "Meta"];
 
-const platformModifiers = isApplePlatform()
+const platformModifiers: string[] = isApplePlatform()
     ? ["Meta", "Alt", "Shift", "Control"]
     : ["Control", "Alt", "Shift", "OS"];
 
+function translateModifierToPlatform(modifier: Modifier): string {
+    return platformModifiers[allModifiers.indexOf(modifier)];
+}
 
 export const checkModifiers =
     (required: Modifier[], optional: Modifier[] = []) =>
@@ -31,15 +33,18 @@ export const checkModifiers =
         );
     };
 
-export const hasModifier = (modifier: Modifier) => (event: KeyboardEvent): boolean => event.getModifierState(platformModifiers[allModifiers.indexOf(modifier)]);
+const modifierPressed =
+    (modifier: Modifier) =>
+    (event: MouseEvent | KeyboardEvent): boolean => {
+        const translated = translateModifierToPlatform(modifier);
+        const state = event.getModifierState(translated);
+        return event.type === "keyup"
+            ? state && (event as KeyboardEvent).key !== translated
+            : state;
+    };
 
-export function isControl(key: string): boolean {
-    return key === platformModifiers[0];
-}
-
-export function isShift(key: string): boolean {
-    return key === platformModifiers[2];
-}
+export const controlPressed = modifierPressed("Control");
+export const shiftPressed = modifierPressed("Shift");
 
 export function modifiersToPlatformString(modifiers: string[]): string {
     const displayModifiers = isApplePlatform()