Make field description a placeholder inside EditingArea

ftl/core/fields.ftl

@@ -4,7 +4,7 @@ fields-editing-font = Editing Font
 fields-field = Field:
 fields-field-name = Field name:
 fields-description = Description
-fields-description-placeholder = Tooltip to show next to the field's name in the editing screen
+fields-description-placeholder = Text to show inside the field when it's empty
 fields-fields-for = Fields for { $val }
 fields-font = Font:
 fields-new-position-1 = New position (1...{ $val }):

ts/editable/ContentEditable.svelte

@@ -7,9 +7,11 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 </script>
 
 <script lang="ts">
-    import type { Writable } from "svelte/store";
+    import { getContext } from "svelte";
+    import type { Readable, Writable } from "svelte/store";
 
     import { updateAllState } from "../components/WithState.svelte";
+    import { descriptionKey } from "../lib/context-keys";
     import actionList from "../sveltelib/action-list";
     import type { MirrorAction } from "../sveltelib/dom-mirror";
     import type { SetupInputHandlerAction } from "../sveltelib/input-handler";
@@ -33,10 +35,18 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     const [focusHandler, setupFocusHandling] = useFocusHandler();
 
     Object.assign(api, { focusHandler });
+
+    const description = getContext<Readable<string>>(descriptionKey);
+    $: descriptionCSSValue = `"${$description}"`;
+
+    let innerHTML = "";
+    $: empty = ["", "<br>"].includes(innerHTML);
 </script>
 
 <anki-editable
+    class:empty
     contenteditable="true"
+    bind:innerHTML
     use:resolve
     use:setupFocusHandling
     use:preventBuiltinShortcuts
@@ -46,11 +56,13 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     on:blur
     on:click={updateAllState}
     on:keyup={updateAllState}
+    style="--description: {descriptionCSSValue}"
 />
 
 <style lang="scss">
     anki-editable {
         display: block;
+        position: relative;
         padding: 6px;
         overflow: auto;
         overflow-wrap: anywhere;
@@ -60,6 +72,17 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
         &:focus {
             outline: none;
         }
+        &.empty::before {
+            content: var(--description);
+            opacity: 0.4;
+            cursor: text;
+            /* stay on single line */
+            position: absolute;
+            max-width: 95%;
+            overflow-x: hidden;
+            white-space: nowrap;
+            text-overflow: ellipsis;
+        }
     }
 
     /* editable-base.scss contains styling targeting user HTML */

ts/editor/EditorField.svelte

@@ -10,10 +10,10 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
     export interface FieldData {
         name: string;
-        description: string;
         fontFamily: string;
         fontSize: number;
         direction: "ltr" | "rtl";
+        description: string;
     }
 
     export interface EditorFieldAPI {
@@ -33,13 +33,12 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     import type { Writable } from "svelte/store";
     import { writable } from "svelte/store";
 
-    import { directionKey } from "../lib/context-keys";
+    import { descriptionKey, directionKey } from "../lib/context-keys";
     import { promiseWithResolver } from "../lib/promise";
     import type { Destroyable } from "./destroyable";
     import EditingArea from "./EditingArea.svelte";
     import FieldState from "./FieldState.svelte";
     import LabelContainer from "./LabelContainer.svelte";
-    import LabelDescription from "./LabelDescription.svelte";
     import LabelName from "./LabelName.svelte";
 
     export let content: Writable<string>;
@@ -50,6 +49,11 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
     $: $directionStore = field.direction;
 
+    const descriptionStore = writable<string>();
+    setContext(descriptionKey, descriptionStore);
+
+    $: $descriptionStore = field.description;
+
     const editingArea: Partial<EditingAreaAPI> = {};
     const [element, elementResolve] = promiseWithResolver<HTMLElement>();
 
@@ -79,9 +83,6 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
             <LabelName>
                 {field.name}
             </LabelName>
-            {#if field.description}
-                <LabelDescription description={field.description} />
-            {/if}
         </span>
         <FieldState><slot name="field-state" /></FieldState>
     </LabelContainer>

ts/editor/icons.ts

@@ -12,4 +12,3 @@ export { default as richTextOn } from "@mdi/svg/svg/eye-outline.svg";
 export { default as stickyOff } from "@mdi/svg/svg/pin-off-outline.svg";
 export { default as stickyOn } from "@mdi/svg/svg/pin-outline.svg";
 export { default as htmlOff } from "@mdi/svg/svg/xml.svg";
-export { default as descriptionIcon } from "bootstrap-icons/icons/info-circle.svg";

ts/lib/context-keys.ts

@@ -4,3 +4,4 @@
 export const fontFamilyKey = Symbol("fontFamily");
 export const fontSizeKey = Symbol("fontSize");
 export const directionKey = Symbol("direction");
+export const descriptionKey = Symbol("description");