[FIX] mail: prevent composer cursor from randomly changing position

task-2388600

closes odoo/odoo#64830

X-original-commit: 785fdb6cea6ee7d9a1a4e4c6a44403a275a67763
Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>

addons/mail/static/src/components/composer_text_input/composer_text_input.js

@@ -163,14 +163,16 @@ class ComposerTextInput extends Component {
         if (!this.composer) {
             return;
         }
-        this._textareaRef.el.value = this.composer.textInputContent;
-        this._mirroredTextareaRef.el.value = this.composer.textInputContent;
-        if (this.composer.hasFocus) {
-            this._textareaRef.el.setSelectionRange(
-                this.composer.textInputCursorStart,
-                this.composer.textInputCursorEnd,
-                this.composer.textInputSelectionDirection,
-            );
+        if (this.composer.isLastStateChangeProgrammatic) {
+            this._textareaRef.el.value = this.composer.textInputContent;
+            if (this.composer.hasFocus) {
+                this._textareaRef.el.setSelectionRange(
+                    this.composer.textInputCursorStart,
+                    this.composer.textInputCursorEnd,
+                    this.composer.textInputSelectionDirection,
+                );
+            }
+            this.composer.update({ isLastStateChangeProgrammatic: false });
         }
         this._updateHeight();
     }
@@ -181,6 +183,7 @@ class ComposerTextInput extends Component {
      * @private
      */
     _updateHeight() {
+        this._mirroredTextareaRef.el.value = this.composer.textInputContent;
         this._textareaRef.el.style.height = (this._mirroredTextareaRef.el.scrollHeight) + "px";
     }
 

addons/mail/static/src/models/composer/composer.js

@@ -160,6 +160,7 @@ function factory(dependencies) {
                 this.textInputContent.length
             );
             this.update({
+                isLastStateChangeProgrammatic: true,
                 textInputContent: partA + content + partB,
                 textInputCursorStart: this.textInputCursorStart + content.length,
                 textInputCursorEnd: this.textInputCursorStart + content.length,
@@ -208,6 +209,7 @@ function factory(dependencies) {
                     break;
             }
             this.update({
+                isLastStateChangeProgrammatic: true,
                 textInputContent: textLeft + recordReplacement + ' ' + textRight,
                 textInputCursorEnd: textLeft.length + recordReplacement.length + 1,
                 textInputCursorStart: textLeft.length + recordReplacement.length + 1,
@@ -722,6 +724,7 @@ function factory(dependencies) {
             this.closeSuggestions();
             this.update({
                 attachments: [['unlink-all']],
+                isLastStateChangeProgrammatic: true,
                 mentionedChannels: [['unlink-all']],
                 mentionedPartners: [['unlink-all']],
                 subjectContent: "",
@@ -1011,6 +1014,16 @@ function factory(dependencies) {
         hasToScrollToActiveSuggestion: attr({
             default: false,
         }),
+        /**
+         * Determines whether the last change (since the last render) was
+         * programmatic. Useful to avoid restoring the state when its change was
+         * from a user action, in particular to prevent the cursor from jumping
+         * to its previous position after the user clicked on the textarea while
+         * it didn't have the focus anymore.
+         */
+        isLastStateChangeProgrammatic: attr({
+            default: false,
+        }),
         /**
          * If true composer will log a note, else a comment will be posted.
          */