UPDATE: Adds web app (#79)

Things missing:

* Browse mode
* Front end tests
* Storybook

base/src/test/user_model/test_keyboard_navigation.rs

@@ -0,0 +1,136 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::{
+    constants::{
+        DEFAULT_COLUMN_WIDTH, DEFAULT_ROW_HEIGHT, DEFAULT_WINDOW_HEIGH, DEFAULT_WINDOW_WIDTH,
+        LAST_COLUMN,
+    },
+    test::util::new_empty_model,
+    UserModel,
+};
+
+#[test]
+fn basic_navigation() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+    model.on_arrow_right().unwrap();
+    let view = model.get_selected_view();
+    assert_eq!(view.range, [1, 2, 1, 2]);
+    assert_eq!(view.column, 2);
+    assert_eq!(view.row, 1);
+
+    model.on_arrow_left().unwrap();
+    let view = model.get_selected_view();
+    assert_eq!(view.range, [1, 1, 1, 1]);
+    assert_eq!(view.column, 1);
+    assert_eq!(view.row, 1);
+
+    model.on_arrow_left().unwrap();
+    let view = model.get_selected_view();
+    assert_eq!(view.range, [1, 1, 1, 1]);
+    assert_eq!(view.column, 1);
+    assert_eq!(view.row, 1);
+
+    model.on_arrow_down().unwrap();
+    let view = model.get_selected_view();
+    assert_eq!(view.range, [2, 1, 2, 1]);
+    assert_eq!(view.column, 1);
+    assert_eq!(view.row, 2);
+
+    model.on_arrow_up().unwrap();
+    let view = model.get_selected_view();
+    assert_eq!(view.range, [1, 1, 1, 1]);
+    assert_eq!(view.column, 1);
+    assert_eq!(view.row, 1);
+
+    model.on_arrow_up().unwrap();
+    let view = model.get_selected_view();
+    assert_eq!(view.range, [1, 1, 1, 1]);
+    assert_eq!(view.column, 1);
+    assert_eq!(view.row, 1);
+}
+
+#[test]
+fn scroll_right() {
+    let window_width = DEFAULT_WINDOW_WIDTH as f64;
+    let column_width = DEFAULT_COLUMN_WIDTH;
+    let column_count = f64::floor(window_width / column_width) as i32;
+
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+    model.on_arrow_right().unwrap();
+
+    model.set_selected_cell(3, column_count).unwrap();
+    model.on_arrow_right().unwrap();
+    let view = model.get_selected_view();
+    assert_eq!(view.left_column, 2);
+
+    model.on_arrow_right().unwrap();
+    let view = model.get_selected_view();
+    assert_eq!(view.left_column, 3);
+}
+
+#[test]
+fn last_colum() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+    model.set_selected_cell(3, LAST_COLUMN).unwrap();
+    let view = model.get_selected_view();
+    assert_eq!(view.column, LAST_COLUMN);
+
+    model.on_arrow_right().unwrap();
+    let view = model.get_selected_view();
+    assert_eq!(view.column, LAST_COLUMN);
+}
+
+#[test]
+fn page_down() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+    let window_height = DEFAULT_WINDOW_HEIGH as f64;
+    let row_height = DEFAULT_ROW_HEIGHT;
+    let row_count = f64::floor(window_height / row_height) as i32;
+    model.on_page_down().unwrap();
+
+    let view = model.get_selected_view();
+    assert_eq!(view.row, 1 + row_count);
+    let scroll_y = model.get_scroll_y().unwrap();
+    assert_eq!(scroll_y, (row_count as f64) * DEFAULT_ROW_HEIGHT);
+}
+
+// we just test that page up and page down are inverse operations
+#[test]
+fn page_up() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+    model.on_page_down().unwrap();
+    let row1 = model.get_selected_view().row;
+
+    model.on_page_down().unwrap();
+    let row2 = model.get_selected_view().row;
+
+    model.on_page_down().unwrap();
+    let row3 = model.get_selected_view().row;
+
+    model.on_page_down().unwrap();
+
+    model.on_page_up().unwrap();
+    assert_eq!(model.get_selected_view().row, row3);
+
+    model.on_page_up().unwrap();
+    assert_eq!(model.get_selected_view().row, row2);
+
+    model.on_page_up().unwrap();
+    assert_eq!(model.get_selected_view().row, row1);
+
+    model.on_page_up().unwrap();
+    assert_eq!(model.get_selected_view().row, 1);
+}
+
+#[test]
+fn page_up_fails_on_row1() {
+    let model = new_empty_model();
+    let mut model = UserModel::from_model(model);
+    model.on_arrow_up().unwrap();
+    assert_eq!(model.get_selected_view().row, 1);
+}