Introduce new zoom mode: custom

Fixes baskerville#126.

doc/MANUAL.md

@@ -93,6 +93,11 @@ Swipe north/south to scroll the page stream when the zoom mode is fit-to-width.
 Rotate to change the screen orientation (one finger is the center, the other describes the desired rotation with a circular motion around the center: the two fingers should land and take off simultaneously).
 
 Spread (resp. pinch) horizontally to switch the zoom mode to fit-to-width (resp. fit-to-page).
+Spread (resp. pinch) diagonally to zoom in (resp. out) on the current page (the zoom mode is set to *custom*).
+
+When the zoom mode is *custom*:
+- Tapping a peripheral region moves the view port in the corresponding direction.
+- Swiping moves the view port in the swipe's opposite direction.
 
 The following swipe sequences are recognized:
 

src/emulator.rs

@@ -34,6 +34,7 @@ use sdl2::event::Event as SdlEvent;
 use sdl2::keyboard::{Scancode, Keycode};
 use sdl2::render::{WindowCanvas, BlendMode};
 use sdl2::pixels::{Color as SdlColor, PixelFormatEnum};
+use sdl2::mouse::MouseState;
 use sdl2::rect::Point as SdlPoint;
 use sdl2::rect::Rect as SdlRect;
 use crate::framebuffer::{Framebuffer, UpdateMode};
@@ -56,8 +57,8 @@ use crate::view::common::{locate, locate_by_id, transfer_notifications, overlapp
 use crate::view::common::{toggle_input_history_menu, toggle_keyboard_layout_menu};
 use crate::helpers::{load_toml, save_toml};
 use crate::settings::{Settings, SETTINGS_PATH};
-use crate::geom::Rectangle;
-use crate::gesture::gesture_events;
+use crate::geom::{Rectangle, Axis};
+use crate::gesture::{GestureEvent, gesture_events};
 use crate::device::CURRENT_DEVICE;
 use crate::battery::{Battery, FakeBattery};
 use crate::frontlight::{Frontlight, LightLevels};
@@ -274,7 +275,8 @@ fn main() -> Result<(), Error> {
  let mut bus = VecDeque::with_capacity(4);
 
  'outer: loop {
- if let Some(sdl_evt) = sdl_context.event_pump().unwrap().wait_event_timeout(20) {
+ let mut event_pump = sdl_context.event_pump().unwrap();
+ if let Some(sdl_evt) = event_pump.wait_event_timeout(20) {
  match sdl_evt {
  SdlEvent::Quit { .. } |
  SdlEvent::KeyDown { keycode: Some(Keycode::Escape), .. } => {
@@ -297,6 +299,21 @@ fn main() -> Result<(), Error> {
  Scancode::S => {
  tx.send(Event::Select(EntryId::TakeScreenshot)).ok();
  },
+ Scancode::I | Scancode::O => {
+ let mouse_state = MouseState::new(&event_pump);
+ let x = mouse_state.x() as i32;
+ let y = mouse_state.y() as i32;
+ let center = pt!(x, y);
+ if scancode == Scancode::I {
+ tx.send(Event::Gesture(GestureEvent::Spread { center,
+ factor: 2.0,
+ axis: Axis::Diagonal })).ok();
+ } else {
+ tx.send(Event::Gesture(GestureEvent::Pinch { center,
+ factor: 0.5,
+ axis: Axis::Diagonal })).ok();
+ }
+ },
  _ => (),
  }
  },

src/geom.rs

@@ -108,7 +108,7 @@ impl LinearDir {
  }
 }
 
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Serialize, Deserialize)]
 pub struct Point {
  pub x: i32,
  pub y: i32,

src/metadata.rs

@@ -10,6 +10,7 @@ use fxhash::FxHashMap;
 use serde::{Serialize, Deserialize};
 use lazy_static::lazy_static;
 use titlecase::titlecase;
+use crate::geom::Point;
 use crate::document::{Document, SimpleTocEntry, TextLocation};
 use crate::document::asciify;
 use crate::document::epub::EpubDocument;
@@ -199,7 +200,7 @@ pub struct ReaderInfo {
  #[serde(skip_serializing_if = "Option::is_none")]
  pub zoom_mode: Option<ZoomMode>,
  #[serde(skip_serializing_if = "Option::is_none")]
- pub top_offset: Option<i32>,
+ pub page_offset: Option<Point>,
  #[serde(skip_serializing_if = "Option::is_none")]
  pub rotation: Option<i8>,
  #[serde(skip_serializing_if = "Option::is_none")]
@@ -228,12 +229,26 @@ pub struct ReaderInfo {
  pub annotations: Vec<Annotation>,
 }
 
-#[derive(Serialize, Deserialize, Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Serialize, Deserialize, Debug, Copy, Clone)]
 pub enum ZoomMode {
  FitToPage,
  FitToWidth,
+ Custom(f32),
 }
 
+impl PartialEq for ZoomMode {
+ fn eq(&self, other: &Self) -> bool {
+ match (self, other) {
+ (ZoomMode::FitToPage, ZoomMode::FitToPage) => true,
+ (ZoomMode::FitToWidth, ZoomMode::FitToWidth) => true,
+ (ZoomMode::Custom(z1), ZoomMode::Custom(z2)) => (z1 - z2).abs() < f32::EPSILON,
+ _ => false,
+ }
+ }
+}
+
+impl Eq for ZoomMode {}
+
 impl ReaderInfo {
  pub fn progress(&self) -> f32 {
  (self.current_page / self.pages_count) as f32
@@ -248,7 +263,7 @@ impl Default for ReaderInfo {
  pages_count: 1,
  finished: false,
  zoom_mode: None,
- top_offset: None,
+ page_offset: None,
  rotation: None,
  cropping_margins: None,
  margin_width: None,