feat(srcts): Show keyboard shortcuts in a popup (#73)

NEWS.md

@@ -6,6 +6,8 @@
 
 - Migrated project license from GPL-3 to the MIT License.
 
+- Added a `?` button to the reactlog header. Hover over it or click it to see every keyboard shortcut, with key names for your operating system. The navigation button tooltips now also use your operating system's key names. The vignette has the same list (#73)
+
 - Documented that `reactlog_show()` passes `...` on to `reactlog_render()`, so `session_token` can be set from `reactlog_show()`. The docs used to say `...` was ignored (#120)
 
 - Fixed `reactlog_render()` printing "Loading required namespace: shiny" (#120)

inst/reactlog/reactlog.html

@@ -46,6 +46,10 @@
       <div id="filter">
         <input id="search" type="text" size="12" placeholder="Search Labels..."/>
       </div>
+      <div id="shortcuts">
+        <button id="shortcutsButton" type="button" aria-label="Keyboard shortcuts" aria-expanded="false" aria-controls="shortcutsPopup">?</button>
+        <div id="shortcutsPopup"></div>
+      </div>
     </div> <!-- end statusHeader -->
 
     <div id="timeline" style="z-index:1;">

inst/reactlog/reactlogAsset/reactlog.css

@@ -197,6 +197,54 @@ text {
   margin-left: 5px;
   margin-right: 5px;
 }
+#shortcuts {
+  position: relative;
+  margin-right: 8px;
+}
+#shortcutsButton {
+  display: block;
+  width: 16px;
+  height: 16px;
+  padding: 0;
+  border: 1px solid #d0d0d0;
+  border-radius: 50%;
+  background: transparent;
+  color: #a0a0a0;
+  font-family: inherit;
+  font-size: 11px;
+  line-height: 14px;
+  cursor: pointer;
+}
+#shortcutsButton:hover,
+#shortcuts.open #shortcutsButton {
+  border-color: #a0a0a0;
+  color: #606060;
+}
+#shortcutsPopup {
+  display: none;
+  position: absolute;
+  top: 100%;
+  right: 0;
+  z-index: 2000;
+  padding: 8px 12px;
+  background: #fff;
+  border: 1px solid #d0d0d0;
+  border-radius: 5px;
+  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
+  font-size: 12px;
+}
+#shortcuts:hover #shortcutsPopup,
+#shortcuts.open #shortcutsPopup {
+  display: block;
+}
+#shortcutsPopup th {
+  text-align: left;
+  font-weight: 600;
+  padding: 8px 0 4px;
+}
+#shortcutsPopup td {
+  padding: 2px 12px 2px 0;
+}
 #search {
   background: url("images/iconSearch.svg") no-repeat scroll 0 0;
   background-size: 20px 20px;

srcts/index.ts

@@ -12,6 +12,7 @@ import colors from "./style/colors";
 import * as cytoscapeInit from "./cyto/cytoscapeInit";
 
 import * as layoutKeydown from "./layout/keydown";
+import * as shortcuts from "./layout/shortcuts";
 
 import * as updateGraph from "./updateGraph";
 
@@ -128,6 +129,7 @@ $(function () {
   );
 
   updateGraph.searchStringContainer($("#search"));
+  shortcuts.setup();
 
   {
     let docBody = document.body;

srcts/layout/shortcuts.ts

@@ -0,0 +1,102 @@
+import $ from "jquery";
+
+const isMac = /Mac|iPhone|iPad/.test(navigator.userAgent);
+
+const alt = isMac ? "Option" : "Alt";
+const shift = "Shift";
+const ctrl = isMac ? "Cmd" : "Ctrl";
+// Mac laptops have no Home / End keys
+const home = isMac ? ["Fn", "←"] : ["Home"];
+const end = isMac ? ["Fn", "→"] : ["End"];
+
+let comboText = function (keys: string[]): string {
+  return keys.join(" + ");
+};
+
+// each row: alternative key combos, then the action
+type Row = [string[][], string];
+
+const reactlogRows: Row[] = [
+  [[["→"], ["Space"]], "Next step"],
+  [[["←"]], "Previous step"],
+  [
+    [
+      [shift, "←"],
+      [shift, "→"],
+    ],
+    "Previous / next log entry",
+  ],
+  [
+    [
+      [alt, "←"],
+      [alt, "→"],
+    ],
+    "Previous / next output calculation",
+  ],
+  [
+    [
+      [alt, shift, "←"],
+      [alt, shift, "→"],
+    ],
+    "Previous / next idle",
+  ],
+  [[home, end], "Previous / next user mark"],
+  [[["s"]], "Focus the search bar"],
+  [[["Esc"]], "Leave search; clear highlight and filter"],
+  [[["f"]], "Fit the graph to the window"],
+  [[["l"]], "Show / hide log entry details"],
+];
+const shinyRows: Row[] = [
+  [[[ctrl, "F3"]], "Open reactlog"],
+  [
+    [
+      [ctrl, shift, "F3"],
+      [ctrl, "F4"],
+    ],
+    "Add a user mark",
+  ],
+];
+
+let sectionHtml = function (title: string, rows: Row[]): string {
+  let body = rows
+    .map(
+      ([combos, action]) =>
+        `<tr><td class="monospaced-pre">${combos.map(comboText).join(" / ")}</td><td>${action}</td></tr>`
+    )
+    .join("");
+  return `<tr><th colspan="2">${title}</th></tr>${body}`;
+};
+
+let setup = function (): void {
+  $("#shortcutsPopup").html(
+    "<table>" +
+      sectionHtml("Keyboard shortcuts", reactlogRows) +
+      sectionHtml("In the Shiny app", shinyRows) +
+      "</table>"
+  );
+
+  let wrapper = $("#shortcuts");
+  $("#shortcutsButton").on("click", function () {
+    wrapper.toggleClass("open");
+    $(this).attr("aria-expanded", String(wrapper.hasClass("open")));
+    // keep focus off the button so Space / arrow keys still move the graph
+    $(this).trigger("blur");
+  });
+
+  // navigation button tooltips
+  let titles: [string, string, string[]][] = [
+    ["prevUserMarkButton", "Previous User Mark", home],
+    ["prevIdleButton", "Previous idle", [alt, shift, "←"]],
+    ["prevOutputCalcButton", "Previous output calculation", [alt, "←"]],
+    ["prevStepButton", "Previous step", ["←"]],
+    ["nextStepButton", "Next step", ["→"]],
+    ["nextOutputCalcButton", "Next output calculation", [alt, "→"]],
+    ["nextIdleButton", "Next idle", [alt, shift, "→"]],
+    ["nextUserMarkButton", "Next User Mark", end],
+  ];
+  titles.forEach(([id, label, keys]) => {
+    $(`#${id}`).attr("title", `${label} (${comboText(keys)})`);
+  });
+};
+
+export { setup };

vignettes/reactlog.Rmd

@@ -276,6 +276,8 @@ knitr::include_graphics("images/navigation.png")
 
 > Tip: Hold `SHIFT` with the `Left/Right Arrow keys` to move one log entry at a time, including entries that are not shown as their own step.
 
+> All key bindings are listed in [Keyboard shortcuts](#keyboard-shortcuts).
+
 ##### Search Bar
 
 The search bar matches the name or ID of each reactive graph element. All matching elements are increased in size to signify a match and all matching elements' family trees are displayed. The search becomes active after three characters, and if no matches are found, the full graph is displayed.
@@ -349,6 +351,32 @@ knitr::include_graphics("images/elements.png")
 
 Fortunately, **shiny**'s `reactive()` and `observe()` functions have a `label` argument. If provided, **reactlog** will use this value to label the corresponding nodes.
 
+### Keyboard shortcuts {#keyboard-shortcuts}
+
+Hover over or click the `?` button at the top right of **reactlog** to see these shortcuts with the key names for your computer.
+
+Inside the **shiny** application (Mac users: use `Cmd` in place of `Ctrl`):
+
+| Keys | Action |
+|------|--------|
+| `Ctrl + F3` | Open **reactlog** |
+| `Ctrl + Shift + F3` or `Ctrl + F4` | Add a user mark at the current time |
+
+Inside **reactlog** (`Alt` is `Option` on a Mac):
+
+| Keys | Action |
+|------|--------|
+| `Right Arrow` or `Space` | Next step |
+| `Left Arrow` | Previous step |
+| `Shift + Left/Right Arrow` | Previous / next log entry, including entries that are not shown as their own step |
+| `Alt + Left/Right Arrow` | Previous / next reactive endpoint calculation |
+| `Alt + Shift + Left/Right Arrow` | Previous / next idle step |
+| `Home` / `End` | Previous / next user mark (or the start / end of the log) |
+| `s` | Focus the search bar |
+| `Esc` | Leave the search bar; otherwise clear the highlight and filter |
+| `f` | Fit the graph to the window |
+| `l` | Show or hide detailed information about the current step |
+
 ## Learn more {#learn-more}
 
 This vignette explains the **reactlog** interface, which requires a basic understanding of **shiny** and reactive programming. There are many other useful existing articles and resources that may help advance your understanding of **reactlog** and **shiny**, including but not limited to: