Bug 1940052 - Apply fixed position css to Android pip media query r=emilio,twisniewski

Differential Revision: https://phabricator.services.mozilla.com/D246364

dom/ipc/BrowserChild.cpp

@@ -29,6 +29,7 @@
 #include "mozilla/LookAndFeel.h"
 #include "mozilla/MouseEvents.h"
 #include "mozilla/widget/ScreenManager.h"
+#include "mozilla/MediaFeatureChange.h"
 #include "mozilla/NativeKeyBindingsType.h"
 #include "mozilla/NullPrincipal.h"
 #include "mozilla/PointerLockManager.h"
@@ -1264,6 +1265,11 @@ mozilla::ipc::IPCResult BrowserChild::RecvAndroidPipModeChanged(bool aPipMode) {
   }
   mInAndroidPipMode = aPipMode;
   if (RefPtr<Document> document = GetTopLevelDocument()) {
+    if (nsPresContext* presContext = document->GetPresContext()) {
+      presContext->MediaFeatureValuesChanged(
+          {MediaFeatureChangeReason::DisplayModeChange},
+          MediaFeatureChangePropagation::JustThisDocument);
+    }
     nsContentUtils::DispatchEventOnlyToChrome(
         document, document,
         aPipMode ? u"MozAndroidPipModeEntered"_ns

layout/style/GeckoBindings.h

@@ -616,6 +616,7 @@ mozilla::PointerCapabilities Gecko_MediaFeatures_AllPointerCapabilities(
 float Gecko_MediaFeatures_GetDevicePixelRatio(const mozilla::dom::Document*);
 
 bool Gecko_MediaFeatures_IsResourceDocument(const mozilla::dom::Document*);
+bool Gecko_MediaFeatures_InAndroidPipMode(const mozilla::dom::Document*);
 bool Gecko_MediaFeatures_MatchesPlatform(mozilla::StylePlatform);
 mozilla::StyleGtkThemeFamily Gecko_MediaFeatures_GtkThemeFamily();
 

layout/style/nsMediaFeatures.cpp

@@ -96,6 +96,10 @@ bool Gecko_MediaFeatures_IsResourceDocument(const Document* aDocument) {
   return aDocument->IsResourceDoc();
 }
 
+bool Gecko_MediaFeatures_InAndroidPipMode(const Document* aDocument) {
+  return aDocument->InAndroidPipMode();
+}
+
 bool Gecko_MediaFeatures_UseOverlayScrollbars(const Document* aDocument) {
   nsPresContext* pc = aDocument->GetPresContext();
   return pc && pc->UseOverlayScrollbars();

layout/style/res/html.css

@@ -205,6 +205,27 @@ h6 {
   margin-block: 2.33em;
 }
 
+/* properties from https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/css/fullscreen.css;l=68-83;drc=4670338ccf46aaf26aee2402b0f722106d55b003  */
+/* stylelint-disable-next-line media-query-no-invalid */
+@media (-moz-in-android-pip-mode) and -moz-pref("layout.css.android-pip.enabled") {
+  video {
+    position: fixed !important;
+    left: 0 !important;
+    top: 0 !important;
+    margin: 0 !important;
+    min-width: 0 !important;
+    max-width: none !important;
+    min-height: 0 !important;
+    max-height: none !important;
+    width: 100% !important;
+    height: 100% !important;
+    transform: none !important;
+
+    background-color: black !important;
+    z-index: 2147483647 !important;
+  }
+}
+
 /* stylelint-disable-next-line media-query-no-invalid */
 @media -moz-pref("layout.css.h1-in-section-ua-styles.enabled") {
   :is(article, aside, nav, section)

layout/style/test/chrome/chrome-only-media-queries.js

@@ -1,5 +1,6 @@
 const CHROME_ONLY_TOGGLES = [
   "-moz-is-glyph",
+  "-moz-in-android-pip-mode",
   "-moz-print-preview",
   "-moz-scrollbar-start-backward",
   "-moz-scrollbar-start-forward",

modules/libpref/init/StaticPrefList.yaml

@@ -10170,6 +10170,12 @@
   value: @IS_NOT_NIGHTLY_BUILD@
   mirror: always
 
+# CSS for android picture-in-picture. See bug 1940052.
+- name: layout.css.android-pip.enabled
+  type: RelaxedAtomicBool
+  value: true
+  mirror: always
+
 # The maximum width or height of the cursor we should allow when intersecting
 # the UI, in CSS pixels.
 - name: layout.cursor.block.max-size

servo/components/style/gecko/media_features.rs

@@ -515,6 +515,10 @@ fn eval_moz_is_glyph(context: &Context) -> bool {
     context.device().document().mIsSVGGlyphsDocument()
 }
 
+fn eval_moz_in_android_pip_mode(context: &Context) -> bool {
+    unsafe { bindings::Gecko_MediaFeatures_InAndroidPipMode(context.device().document()) }
+}
+
 fn eval_moz_print_preview(context: &Context) -> bool {
     let is_print_preview = context.device().is_print_preview();
     if is_print_preview {
@@ -653,7 +657,7 @@ macro_rules! lnf_int_feature {
 /// to support new types in these entries and (2) ensuring that either
 /// nsPresContext::MediaFeatureValuesChanged is called when the value that
 /// would be returned by the evaluator function could change.
-pub static MEDIA_FEATURES: [QueryFeatureDescription; 61] = [
+pub static MEDIA_FEATURES: [QueryFeatureDescription; 62] = [
     feature!(
         atom!("width"),
         AllowsRanges::Yes,
@@ -888,6 +892,12 @@ pub static MEDIA_FEATURES: [QueryFeatureDescription; 61] = [
         Evaluator::BoolInteger(eval_moz_is_glyph),
         FeatureFlags::CHROME_AND_UA_ONLY,
     ),
+    feature!(
+        atom!("-moz-in-android-pip-mode"),
+        AllowsRanges::No,
+        Evaluator::BoolInteger(eval_moz_in_android_pip_mode),
+        FeatureFlags::CHROME_AND_UA_ONLY,
+    ),
     feature!(
         atom!("-moz-is-resource-document"),
         AllowsRanges::No,

xpcom/ds/StaticAtoms.py

@@ -55,6 +55,7 @@ STATIC_ATOMS = [
     Atom("mozsignature", "moz-signature"),  # Used by MailNews.
     Atom("_moz_bullet_font", "-moz-bullet-font"),
     Atom("_moz_is_glyph", "-moz-is-glyph"),
+    Atom("_moz_in_android_pip_mode", "-moz-in-android-pip-mode"),
     Atom("_moz_original_size", "_moz_original_size"),
     Atom("_moz_print_preview", "-moz-print-preview"),
     Atom("menuactive", "_moz-menuactive"),
@@ -2441,6 +2442,7 @@ STATIC_ATOMS = [
     Atom("layout_css_always_underline_links", "layout.css.always_underline_links"),
     Atom("layout_css_cached_scrollbar_styles_enabled", "layout.css.cached-scrollbar-styles.enabled"),
     Atom("layout_css_h1_in_section_ua_styles_enabled", "layout.css.h1-in-section-ua-styles.enabled"),
+    Atom("layout_css_android_pip_enabled", "layout.css.android-pip.enabled"),
     # Contextual Identity / Containers
     Atom("usercontextid", "usercontextid"),
     Atom("geckoViewSessionContextId", "geckoViewSessionContextId"),