From 434c793d1c29e46fdbc52140a6db2d5386f3ed85 Mon Sep 17 00:00:00 2001
From: Stephan Dilly <dilly.stephan@gmail.com>
Date: Tue, 12 May 2020 01:21:32 +0200
Subject: [PATCH] support page up/down in log (#43)

---
 src/app.rs             |  3 ++-
 src/components/diff.rs |  2 ++
 src/components/mod.rs  |  2 ++
 src/keys.rs            |  2 ++
 src/tabs/revlog/mod.rs | 21 +++++++++++++++++++++
 5 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/app.rs b/src/app.rs
index 98ea895d..620b8f8f 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -59,7 +59,7 @@ impl App {
     }
 
     ///
-    pub fn draw<B: Backend>(&self, f: &mut Frame<B>) {
+    pub fn draw<B: Backend>(&mut self, f: &mut Frame<B>) {
         let chunks_main = Layout::default()
             .direction(Direction::Vertical)
             .constraints(
@@ -86,6 +86,7 @@ impl App {
         if self.tab == 0 {
             self.status_tab.draw(f, chunks_main[1]);
         } else {
+            self.revlog.prepare_draw(chunks_main[1]);
             self.revlog.draw(f, chunks_main[1]);
         }
 
diff --git a/src/components/diff.rs b/src/components/diff.rs
index 7ae3374f..db35d861 100644
--- a/src/components/diff.rs
+++ b/src/components/diff.rs
@@ -104,6 +104,8 @@ impl DiffComponent {
             }
             ScrollType::Home => self.scroll = 0,
             ScrollType::End => self.scroll = scroll_max,
+            //TODO:
+            _ => (),
         }
 
         if old != self.scroll {
diff --git a/src/components/mod.rs b/src/components/mod.rs
index dd3ea927..56b33768 100644
--- a/src/components/mod.rs
+++ b/src/components/mod.rs
@@ -57,6 +57,8 @@ pub enum ScrollType {
     Down,
     Home,
     End,
+    PageUp,
+    PageDown,
 }
 
 ///
diff --git a/src/keys.rs b/src/keys.rs
index f87c7a3b..914a5e8c 100644
--- a/src/keys.rs
+++ b/src/keys.rs
@@ -31,6 +31,8 @@ pub const HOME: KeyEvent = no_mod(KeyCode::Home);
 pub const END: KeyEvent = no_mod(KeyCode::End);
 pub const MOVE_UP: KeyEvent = no_mod(KeyCode::Up);
 pub const MOVE_DOWN: KeyEvent = no_mod(KeyCode::Down);
+pub const PAGE_DOWN: KeyEvent = no_mod(KeyCode::PageDown);
+pub const PAGE_UP: KeyEvent = no_mod(KeyCode::PageUp);
 pub const SHIFT_UP: KeyEvent =
     with_mod(KeyCode::Up, KeyModifiers::SHIFT);
 pub const SHIFT_DOWN: KeyEvent =
diff --git a/src/tabs/revlog/mod.rs b/src/tabs/revlog/mod.rs
index 6a49878d..7945514b 100644
--- a/src/tabs/revlog/mod.rs
+++ b/src/tabs/revlog/mod.rs
@@ -53,6 +53,7 @@ pub struct Revlog {
     first_open_done: bool,
     scroll_state: (Instant, f32),
     tags: Tags,
+    current_height: u16,
 }
 
 impl Revlog {
@@ -67,9 +68,15 @@ impl Revlog {
             first_open_done: false,
             scroll_state: (Instant::now(), 0_f32),
             tags: Tags::new(),
+            current_height: 0,
         }
     }
 
+    ///
+    pub fn prepare_draw(&mut self, area: Rect) {
+        self.current_height = area.height.saturating_sub(2);
+    }
+
     ///
     pub fn draw<B: Backend>(&self, f: &mut Frame<B>, area: Rect) {
         let height = area.height as usize;
@@ -155,6 +162,12 @@ impl Revlog {
             ScrollType::Down => {
                 self.selection.saturating_add(speed_int)
             }
+            ScrollType::PageUp => self.selection.saturating_sub(
+                usize::from(self.current_height).saturating_sub(1),
+            ),
+            ScrollType::PageDown => self.selection.saturating_add(
+                usize::from(self.current_height).saturating_sub(1),
+            ),
             ScrollType::Home => 0,
             ScrollType::End => self.selection_max,
         };
@@ -281,6 +294,14 @@ impl Component for Revlog {
                         self.move_selection(ScrollType::End);
                         true
                     }
+                    keys::PAGE_UP => {
+                        self.move_selection(ScrollType::PageUp);
+                        true
+                    }
+                    keys::PAGE_DOWN => {
+                        self.move_selection(ScrollType::PageDown);
+                        true
+                    }
                     _ => false,
                 };
             }