Rollup merge of #92629 - jsha:theme-picker-local-only-2, r=GuillaumeGomez

Pick themes on settings page, not every page

This hides the paintbrush icon on most pages by default, in preference for the settings on the settings page.  When loading from a local file, and not in mobile view, continue to show the theme picker. That's because some browsers limit access to localStorage from file:/// URLs, so choosing a theme from settings.html doesn't take effect.

Fixes #84539
Part of #59840

r? `@GuillaumeGomez`

Demo: https://rustdoc.crud.net/jsha/theme-picker-local-only-2/std/io/trait.Read.html

4 files changed, 46 insertions, 15 deletions

diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 7cc0e74a79b..ed98c0843af 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -1766,6 +1766,12 @@ details.rustdoc-toggle[open] > summary.hideme::after {
 		padding-top: 0px;
 	}
 
+	/* Space is at a premium on mobile, so remove the theme-picker icon. */
+	#theme-picker {
+		display: none;
+		width: 0;
+	}
+
 	.rustdoc {
 		flex-direction: column;
 	}
@@ -1884,12 +1890,6 @@ details.rustdoc-toggle[open] > summary.hideme::after {
 		height: 100%;
 	}
 
-	nav.sub {
-		width: calc(100% - 32px);
-		margin-left: 32px;
-		margin-bottom: 10px;
-	}
-
 	.source nav:not(.sidebar).sub {
 		margin-left: 32px;
 	}
@@ -2086,11 +2086,6 @@ details.rustdoc-toggle[open] > summary.hideme::after {
 		border: 0;
 	}
 
-	#crate-search + .search-input {
-		width: calc(100% + 71px);
-		margin-left: -36px;
-	}
-
 	#theme-picker, #settings-menu {
 		padding: 5px;
 		width: 31px;
diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index f41c1bd817a..011e60b8fa0 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -129,10 +129,15 @@ function hideThemeButtonState() {
 
 // Set up the theme picker list.
 (function () {
+    if (!document.location.href.startsWith("file:///")) {
+        return;
+    }
     var themeChoices = getThemesElement();
     var themePicker = getThemePickerElement();
     var availableThemes = getVar("themes").split(",");
 
+    removeClass(themeChoices.parentElement, "hidden");
+
     function switchThemeButtonState() {
         if (themeChoices.style.display === "block") {
             hideThemeButtonState();
diff --git a/src/librustdoc/html/static/js/settings.js b/src/librustdoc/html/static/js/settings.js
index 4f10e14e855..e5c7e1ea1a0 100644
--- a/src/librustdoc/html/static/js/settings.js
+++ b/src/librustdoc/html/static/js/settings.js
@@ -1,15 +1,18 @@
 // Local js definitions:
 /* global getSettingValue, getVirtualKey, onEachLazy, updateLocalStorage, updateSystemTheme */
+/* global addClass, removeClass */
 
 (function () {
     function changeSetting(settingName, value) {
         updateLocalStorage("rustdoc-" + settingName, value);
 
         switch (settingName) {
+            case "theme":
             case "preferred-dark-theme":
             case "preferred-light-theme":
             case "use-system-theme":
                 updateSystemTheme();
+                updateLightAndDark();
                 break;
         }
     }
@@ -29,7 +32,32 @@
         }
     }
 
+    function showLightAndDark() {
+        addClass(document.getElementById("theme").parentElement.parentElement, "hidden");
+        removeClass(document.getElementById("preferred-light-theme").parentElement.parentElement,
+            "hidden");
+        removeClass(document.getElementById("preferred-dark-theme").parentElement.parentElement,
+            "hidden");
+    }
+
+    function hideLightAndDark() {
+        addClass(document.getElementById("preferred-light-theme").parentElement.parentElement,
+            "hidden");
+        addClass(document.getElementById("preferred-dark-theme").parentElement.parentElement,
+            "hidden");
+        removeClass(document.getElementById("theme").parentElement.parentElement, "hidden");
+    }
+
+    function updateLightAndDark() {
+        if (getSettingValue("use-system-theme") !== "false") {
+            showLightAndDark();
+        } else {
+            hideLightAndDark();
+        }
+    }
+
     function setEvents() {
+        updateLightAndDark();
         onEachLazy(document.getElementsByClassName("slider"), function(elem) {
             var toggle = elem.previousElementSibling;
             var settingId = toggle.id;
diff --git a/src/librustdoc/html/static/js/storage.js b/src/librustdoc/html/static/js/storage.js
index d8b3ba92dcb..2394df4c715 100644
--- a/src/librustdoc/html/static/js/storage.js
+++ b/src/librustdoc/html/static/js/storage.js
@@ -187,22 +187,25 @@ var updateSystemTheme = (function() {
     var mql = window.matchMedia("(prefers-color-scheme: dark)");
 
     function handlePreferenceChange(mql) {
+        let use = function(theme) {
+            switchTheme(window.currentTheme, window.mainTheme, theme, true);
+        };
         // maybe the user has disabled the setting in the meantime!
         if (getSettingValue("use-system-theme") !== "false") {
             var lightTheme = getSettingValue("preferred-light-theme") || "light";
             var darkTheme = getSettingValue("preferred-dark-theme") || "dark";
 
             if (mql.matches) {
-                // prefers a dark theme
-                switchTheme(window.currentTheme, window.mainTheme, darkTheme, true);
+                use(darkTheme);
             } else {
                 // prefers a light theme, or has no preference
-                switchTheme(window.currentTheme, window.mainTheme, lightTheme, true);
+                use(lightTheme);
             }
-
             // note: we save the theme so that it doesn't suddenly change when
             // the user disables "use-system-theme" and reloads the page or
             // navigates to another page
+        } else {
+            use(getSettingValue("theme"));
         }
     }