From db5eefbf00372d5aeda000bf5aeb6e00fa030ed4 Mon Sep 17 00:00:00 2001
From: Sergio Villar Senin <svillar@igalia.com>
Date: Wed, 28 Feb 2024 11:21:28 +0100
Subject: [PATCH] Restore back action using B/Y buttons in non-WebXR mode

In a3f4cb4c we removed the possibility of going back with B/Y buttons
because that was interferring with potential action assignments of
those buttons inside WebXR experiences. We were exiting the WebXR
experience instead of executing the action that was set by authors.

However it turns out that these buttons are heavily used by users
in non-immersive sessions as they're very convenient as you don't
really have to hold both controllers to have full control of your
2D navigation.

Fixes #1266
---
 app/src/main/cpp/BrowserWorld.cpp | 15 +++++++++++++--
 docs/metrics.md                   |  4 ++--
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/app/src/main/cpp/BrowserWorld.cpp b/app/src/main/cpp/BrowserWorld.cpp
index e54a290226..9e284f9114 100644
--- a/app/src/main/cpp/BrowserWorld.cpp
+++ b/app/src/main/cpp/BrowserWorld.cpp
@@ -275,6 +275,17 @@ BrowserWorld::State::SimulateBack() {
     VRBrowser::HandleBack();
 }
 
+static bool
+wasGoBackButtonClicked(const Controller& controller, bool isPresenting) {
+    auto WasButtonPressed = [](const Controller& controller, ControllerDelegate::Button button) {
+        return !(controller.lastButtonState & button) && (controller.buttonState & button);
+    };
+
+    return (WasButtonPressed(controller, ControllerDelegate::BUTTON_APP) ||
+           (!isPresenting && (WasButtonPressed(controller, ControllerDelegate::BUTTON_B) ||
+                              WasButtonPressed(controller, ControllerDelegate::BUTTON_Y))));
+};
+
 void
 BrowserWorld::State::CheckBackButton() {
   for (Controller& controller: controllers->GetControllers()) {
@@ -282,7 +293,7 @@ BrowserWorld::State::CheckBackButton() {
           continue;
       }
 
-    if ((!(controller.lastButtonState & ControllerDelegate::BUTTON_APP) && (controller.buttonState & ControllerDelegate::BUTTON_APP))) {
+    if (wasGoBackButtonClicked(controller, externalVR->IsPresenting())) {
           SimulateBack();
           webXRInterstialState = WebXRInterstialState::HIDDEN;
       } else if (webXRInterstialState == WebXRInterstialState::ALLOW_DISMISS
@@ -423,7 +434,7 @@ BrowserWorld::State::UpdateControllers(bool& aRelayoutWidgets) {
       controller.pointer->Load(device);
     }
 
-    if ((!(controller.lastButtonState & ControllerDelegate::BUTTON_APP) && (controller.buttonState & ControllerDelegate::BUTTON_APP))) {
+    if (wasGoBackButtonClicked(controller, externalVR->IsPresenting())) {
       if (controller.handActionEnabled && !controller.leftHanded) {
           VRBrowser::HandleAppExit();
       } else {
diff --git a/docs/metrics.md b/docs/metrics.md
index d54983a958..864931ba7c 100644
--- a/docs/metrics.md
+++ b/docs/metrics.md
@@ -1,4 +1,4 @@
-<!-- AUTOGENERATED BY glean_parser v11.0.1. DO NOT EDIT. -->
+<!-- AUTOGENERATED BY glean_parser v11.1.0. DO NOT EDIT. -->
 
 # Metrics
 
@@ -11,5 +11,5 @@ This means you might have to go searching through the dependency tree to get a f
 
 Data categories are [defined here](https://wiki.mozilla.org/Firefox/Data_Collection).
 
-<!-- AUTOGENERATED BY glean_parser v11.0.1. DO NOT EDIT. -->
+<!-- AUTOGENERATED BY glean_parser v11.1.0. DO NOT EDIT. -->