textedit: add undo/redo support in textedit

docs/astro/src/content/docs/reference/std-widgets/views/textedit.mdx

@@ -156,6 +156,12 @@ Copies the selected text to the clipboard and removes it from the editable area.
 ### paste()
 Pastes the text content of the clipboard at the cursor position. This function takes effect regardless of the `read-only` and `enabled` properties.
 
+### undo()
+Undoes the last text operation. This function takes effect regardless of the `read-only` and `enabled` properties.
+
+### redo()
+Redoes the last undone text operation. This function takes effect regardless of the `read-only` and `enabled` properties.
+
 ## Callbacks
 
 ### edited(string)

internal/compiler/widgets/common/textedit-base.slint

@@ -59,11 +59,35 @@ export component TextEditBase inherits Rectangle {
         text-input.paste();
     }
 
+    public function undo() {
+        text-input.undo();
+    }
+
+    public function redo() {
+        text-input.redo();
+    }
+
     forward-focus: text-input;
 
     ContextMenuArea {
         enabled: root.enabled;
         Menu {
+            if !root.read-only && root.enabled: MenuItem {
+                title: @tr("Undo");
+                activated => {
+                    text-input.undo();
+                }
+            }
+
+            if !root.read-only && root.enabled: MenuItem {
+                title: @tr("Redo");
+                activated => {
+                    text-input.redo();
+                }
+            }
+
+            if !root.read-only && root.enabled: MenuSeparator { }
+
             MenuItem {
                 title: @tr("Cut");
                 enabled: !root.read-only && root.enabled;

internal/compiler/widgets/cosmic/textedit.slint

@@ -63,6 +63,14 @@ export component TextEdit {
         base.paste();
     }
 
+    public function undo() {
+        base.undo();
+    }
+
+    public function redo() {
+        base.redo();
+    }
+
     forward-focus: base;
     horizontal-stretch: 1;
     vertical-stretch: 1;

internal/compiler/widgets/cupertino/textedit.slint

@@ -117,6 +117,14 @@ export component TextEdit {
         text-input.paste();
     }
 
+    public function undo() {
+        text-input.undo();
+    }
+
+    public function redo() {
+        text-input.redo();
+    }
+
     forward-focus: text-input;
     horizontal-stretch: 1;
     vertical-stretch: 1;
@@ -146,21 +154,35 @@ export component TextEdit {
     }
 
     ContextMenuArea {
+        enabled: root.enabled;
         Menu {
+            if !root.read-only && root.enabled: MenuItem {
+                title: @tr("Undo");
+                activated => { text-input.undo(); }
+            }
+            if !root.read-only && root.enabled: MenuItem {
+                title: @tr("Redo");
+                activated => { text-input.redo(); }
+            }
+            if !root.read-only && root.enabled: MenuSeparator { }
             MenuItem {
                 title: @tr("Cut");
+                enabled: !root.read-only && root.enabled;
                 activated => { text-input.cut(); }
             }
             MenuItem {
                 title: @tr("Copy");
+                enabled: !root.text.is-empty;
                 activated => { text-input.copy(); }
             }
             MenuItem {
                 title: @tr("Paste");
+                enabled: !root.read-only && root.enabled;
                 activated => { text-input.paste(); }
             }
             MenuItem {
                 title: @tr("Select All");
+                enabled: !root.text.is-empty;
                 activated => { text-input.select-all(); }
             }
         }

internal/compiler/widgets/fluent/textedit.slint

@@ -63,6 +63,14 @@ export component TextEdit {
         base.paste();
     }
 
+    public function undo() {
+        base.undo();
+    }
+
+    public function redo() {
+        base.redo();
+    }
+
     forward-focus: base;
     horizontal-stretch: 1;
     vertical-stretch: 1;

internal/compiler/widgets/material/textedit.slint

@@ -63,6 +63,14 @@ export component TextEdit {
         base.paste();
     }
 
+    public function undo() {
+        base.undo();
+    }
+
+    public function redo() {
+        base.redo();
+    }
+
     forward-focus: base;
     horizontal-stretch: 1;
     vertical-stretch: 1;

internal/compiler/widgets/qt/textedit.slint

@@ -62,6 +62,14 @@ export component TextEdit {
         base.paste();
     }
 
+    public function undo() {
+        base.undo();
+    }
+
+    public function redo() {
+        base.redo();
+    }
+
     forward-focus: base;
     horizontal-stretch: 1;
     vertical-stretch: 1;

tests/cases/widgets/textedit.slint

@@ -31,6 +31,12 @@ export component TestCase inherits Window {
     public function select_all() {
         edit.select_all();
     }
+    public function undo() {
+        edit.undo();
+    }
+    public function redo() {
+        edit.redo();
+    }
 }
 
 /*
@@ -41,6 +47,18 @@ use std::cell::RefCell;
 use std::rc::Rc;
 use slint::SharedString;
 
+// Opens the context menu with the menu key and activates the `n`th entry,
+// counting from 1 and skipping separators the way the menu's arrow keys do.
+// Activating a disabled entry leaves the menu open, so this closes it.
+fn menu_activate(instance: &TestCase, n: usize) {
+    slint_testing::send_keyboard_string_sequence(instance, &SharedString::from(slint::platform::Key::Menu));
+    for _ in 0..n {
+        slint_testing::send_keyboard_string_sequence(instance, &SharedString::from(slint::platform::Key::DownArrow));
+    }
+    slint_testing::send_keyboard_string_sequence(instance, "\n");
+    slint_testing::send_keyboard_string_sequence(instance, &SharedString::from(slint::platform::Key::Escape));
+}
+
 fn ctrl_key(instance: &TestCase, key: &str) {
     slint_testing::send_keyboard_char(instance, slint::private_unstable_api::re_exports::Key::Control.into(), true);
     slint_testing::send_keyboard_string_sequence(instance, key);
@@ -99,11 +117,8 @@ slint_testing::send_keyboard_string_sequence(&instance, &SharedString::from(slin
 slint_testing::send_keyboard_string_sequence(&instance, &SharedString::from(slint::platform::Key::UpArrow));
 slint_testing::send_keyboard_string_sequence(&instance, "\n");
 assert_eq!(instance.get_text(), "Hello👋");
-// copy
-slint_testing::send_keyboard_string_sequence(&instance, &SharedString::from(slint::platform::Key::Menu));
-slint_testing::send_keyboard_string_sequence(&instance, &SharedString::from(slint::platform::Key::DownArrow));
-slint_testing::send_keyboard_string_sequence(&instance, &SharedString::from(slint::platform::Key::DownArrow));
-slint_testing::send_keyboard_string_sequence(&instance, "\n");
+// copy: Undo, Redo and a separator come first, so Copy is the fourth entry the arrow keys reach
+menu_activate(&instance, 4);
 assert_eq!(instance.get_text(), "Hello👋");
 
 slint_testing::send_keyboard_string_sequence(&instance, "Xxx");
@@ -143,6 +158,55 @@ assert_eq!(instance.get_font_italic(), true);
 instance.invoke_select_all();
 instance.invoke_cut();
 assert_eq!(instance.get_text(), "");
+
+// undo and redo, through the public functions
+instance.set_enabled(true);
+slint_testing::send_keyboard_string_sequence(&instance, "abc");
+assert_eq!(instance.get_text(), "abc");
+instance.invoke_undo();
+assert_eq!(instance.get_text(), "");
+instance.invoke_redo();
+assert_eq!(instance.get_text(), "abc");
+
+// and through the first two entries of the context menu
+menu_activate(&instance, 1);
+assert_eq!(instance.get_text(), "");
+menu_activate(&instance, 2);
+assert_eq!(instance.get_text(), "abc");
+
+// neither the menu nor Ctrl+Z reaches a read-only or a disabled TextEdit
+instance.invoke_select_all();
+instance.invoke_cut();
+assert_eq!(instance.get_text(), "");
+// the menu above took the keyboard focus away from the TextEdit, so click it back
+slint_testing::send_mouse_click(&instance, 25., 25.);
+instance.set_read_only(true);
+ctrl_key(&instance, "z");
+assert_eq!(instance.get_text(), "");
+// read-only hides Undo and Redo, so the first entry is Cut, which read-only disables
+menu_activate(&instance, 1);
+assert_eq!(instance.get_text(), "");
+instance.set_read_only(false);
+slint_testing::send_mouse_click(&instance, 25., 25.);
+instance.set_enabled(false);
+ctrl_key(&instance, "z");
+assert_eq!(instance.get_text(), "");
+instance.set_enabled(true);
+
+// with neither in the way, the same shortcut undoes the cut
+ctrl_key(&instance, "z");
+assert_eq!(instance.get_text(), "abc");
+
+// with Undo and Redo hidden, a read-only menu lists Cut, Copy, Paste and Select All,
+// so its fourth entry selects the text instead of copying it
+slint_testing::send_mouse_click(&instance, 25., 25.);
+// the undo above left the whole text selected, so collapse the selection first
+slint_testing::send_keyboard_string_sequence(&instance, &SharedString::from(slint::platform::Key::Home));
+instance.set_read_only(true);
+menu_activate(&instance, 4);
+instance.invoke_cut();
+assert_eq!(instance.get_text(), "");
+instance.set_read_only(false);
 ```
 
 */