chore: refactor the input component (#165)

* refactor the input component

* fix clippy

* clean up

crates/ui/src/input/mode.rs

@@ -0,0 +1,129 @@
+use gpui::SharedString;
+
+use super::text_wrapper::TextWrapper;
+
+#[derive(Debug, Copy, Clone)]
+pub struct TabSize {
+    /// Default is 2
+    pub tab_size: usize,
+    /// Set true to use `\t` as tab indent, default is false
+    pub hard_tabs: bool,
+}
+
+impl Default for TabSize {
+    fn default() -> Self {
+        Self {
+            tab_size: 2,
+            hard_tabs: false,
+        }
+    }
+}
+
+impl TabSize {
+    pub(super) fn to_string(self) -> SharedString {
+        if self.hard_tabs {
+            "\t".into()
+        } else {
+            " ".repeat(self.tab_size).into()
+        }
+    }
+}
+
+#[derive(Default, Clone)]
+pub enum InputMode {
+    #[default]
+    SingleLine,
+    MultiLine {
+        tab: TabSize,
+        rows: usize,
+    },
+    AutoGrow {
+        rows: usize,
+        min_rows: usize,
+        max_rows: usize,
+    },
+}
+
+#[allow(unused)]
+impl InputMode {
+    #[inline]
+    pub(super) fn is_single_line(&self) -> bool {
+        matches!(self, InputMode::SingleLine)
+    }
+
+    #[inline]
+    pub(super) fn is_auto_grow(&self) -> bool {
+        matches!(self, InputMode::AutoGrow { .. })
+    }
+
+    #[inline]
+    pub(super) fn is_multi_line(&self) -> bool {
+        matches!(
+            self,
+            InputMode::MultiLine { .. } | InputMode::AutoGrow { .. }
+        )
+    }
+
+    pub(super) fn set_rows(&mut self, new_rows: usize) {
+        match self {
+            InputMode::MultiLine { rows, .. } => {
+                *rows = new_rows;
+            }
+            InputMode::AutoGrow {
+                rows,
+                min_rows,
+                max_rows,
+            } => {
+                *rows = new_rows.clamp(*min_rows, *max_rows);
+            }
+            _ => {}
+        }
+    }
+
+    pub(super) fn update_auto_grow(&mut self, text_wrapper: &TextWrapper) {
+        if self.is_single_line() {
+            return;
+        }
+
+        let wrapped_lines = text_wrapper.len();
+        self.set_rows(wrapped_lines);
+    }
+
+    /// At least 1 row be return.
+    pub(super) fn rows(&self) -> usize {
+        match self {
+            InputMode::MultiLine { rows, .. } => *rows,
+            InputMode::AutoGrow { rows, .. } => *rows,
+            _ => 1,
+        }
+        .max(1)
+    }
+
+    /// At least 1 row be return.
+    #[allow(unused)]
+    pub(super) fn min_rows(&self) -> usize {
+        match self {
+            InputMode::MultiLine { .. } => 1,
+            InputMode::AutoGrow { min_rows, .. } => *min_rows,
+            _ => 1,
+        }
+        .max(1)
+    }
+
+    #[allow(unused)]
+    pub(super) fn max_rows(&self) -> usize {
+        match self {
+            InputMode::MultiLine { .. } => usize::MAX,
+            InputMode::AutoGrow { max_rows, .. } => *max_rows,
+            _ => 1,
+        }
+    }
+
+    #[inline]
+    pub(super) fn tab_size(&self) -> Option<&TabSize> {
+        match self {
+            InputMode::MultiLine { tab, .. } => Some(tab),
+            _ => None,
+        }
+    }
+}