refactor(tui): split app query and viewport cache helpers

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
2026-06-30 16:55:34 +08:00
parent 0910d4e85f
commit 58ac4a65c7
4 changed files with 383 additions and 294 deletions
@@ -0,0 +1,99 @@
+use log_viewer_core::types::LogLevel;
+use unicode_width::UnicodeWidthChar;
+
+pub(super) struct ViewportEntry {
+    pub(super) wrapped_rows: Vec<String>,
+    pub(super) level: Option<LogLevel>,
+    pub(super) visual_height: usize,
+}
+
+pub(super) struct ViewportCache {
+    pub(super) entries: Vec<ViewportEntry>,
+    pub(super) logical_start: usize,
+    pub(super) width: usize,
+    json_format: bool,
+    pub(super) cached_total_visual_rows: Option<usize>,
+}
+
+impl ViewportCache {
+    pub(super) fn new() -> Self {
+        Self {
+            entries: Vec::new(),
+            logical_start: 0,
+            width: 0,
+            json_format: false,
+            cached_total_visual_rows: None,
+        }
+    }
+
+    pub(super) fn invalidate(&mut self) {
+        self.entries.clear();
+        self.logical_start = 0;
+        self.width = 0;
+        self.cached_total_visual_rows = None;
+    }
+
+    pub(super) fn needs_recompute(&self, width: usize, json_format: bool) -> bool {
+        self.width != width || self.json_format != json_format
+    }
+
+    pub(super) fn set_json_format(&mut self, json_format: bool) {
+        self.json_format = json_format;
+    }
+
+    #[allow(dead_code)]
+    pub(super) fn get_entry(&self, logical_line: usize) -> Option<&ViewportEntry> {
+        if logical_line >= self.logical_start {
+            let idx = logical_line - self.logical_start;
+            self.entries.get(idx)
+        } else {
+            None
+        }
+    }
+}
+
+pub(super) const TRUNCATE_TAB_WIDTH: usize = 4;
+
+pub(super) fn gutter_width_for(total_lines: usize, is_loading: bool) -> usize {
+    if total_lines == 0 {
+        return 0;
+    }
+    let line_num_width = total_lines.to_string().len();
+    let loading_extra = if is_loading { 1 } else { 0 };
+    line_num_width + loading_extra + 1 + 1
+}
+
+pub(super) fn truncate_to_columns(s: &str, max_cols: usize) -> String {
+    if max_cols == 0 || s.is_empty() {
+        return String::new();
+    }
+
+    let mut out = String::new();
+    let mut col = 0;
+
+    for ch in s.chars() {
+        if ch == '\t' {
+            let tab_stop = TRUNCATE_TAB_WIDTH - (col % TRUNCATE_TAB_WIDTH);
+            if col + tab_stop > max_cols {
+                break;
+            }
+            for _ in 0..tab_stop {
+                out.push(' ');
+            }
+            col += tab_stop;
+        } else {
+            let w = if ch.is_control() {
+                0
+            } else {
+                ch.width().unwrap_or(0)
+            };
+            if col + w > max_cols {
+                break;
+            }
+            out.push(ch);
+            col += w;
+        }
+    }
+
+    out
+}