Tweak some form fields

Making them required and/or disabled where necessary, and adding some
bounds.

showbits-thermal-printer-ui/src/components/CSegmentCalendar.vue

@@ -25,12 +25,26 @@ function submit() {
 
     <label class="wide">
       Year:
-      <input v-model="year" type="number" :disabled />
+      <input
+        v-model="year"
+        type="number"
+        min="-9999"
+        max="9999"
+        required
+        :disabled
+      />
     </label>
 
     <label class="wide">
       Month:
-      <input v-model="month" type="number" min="1" max="12" :disabled />
+      <input
+        v-model="month"
+        type="number"
+        min="1"
+        max="12"
+        required
+        :disabled
+      />
     </label>
 
     <label><input v-model="feed" type="checkbox" :disabled /> Feed</label>

showbits-thermal-printer-ui/src/components/CSegmentCells.vue

@@ -40,17 +40,32 @@ function submit() {
 
     <label class="wide">
       Rows:
-      <input v-model="rows" type="number" min="1" max="1024" :disabled />
+      <input
+        v-model="rows"
+        type="number"
+        min="1"
+        max="1024"
+        required
+        :disabled
+      />
     </label>
 
     <label class="wide">
       Scale:
-      <input v-model="scale" type="number" min="1" max="16" :disabled />
+      <input
+        v-model="scale"
+        type="number"
+        min="1"
+        max="16"
+        required
+        :disabled
+      />
     </label>
 
     <div class="wide">
       <label>
-        <input v-model="showRule" type="checkbox" :disabled /> Show rule
+        <input v-model="showRule" type="checkbox" :disabled />
+        Show rule
       </label>
       <label><input v-model="feed" type="checkbox" :disabled /> Feed</label>
     </div>

showbits-thermal-printer-ui/src/components/CSegmentChat.vue

@@ -35,9 +35,10 @@ function submit() {
       <input
         v-model="username"
         type="text"
-        required
         minlength="1"
         maxlength="32"
+        required
+        :disabled
       />
     </label>