From 40778d7f299777d5c395e0e742532f214ee5c799 Mon Sep 17 00:00:00 2001
From: Brad Davis <bdavis@saintandreas.org>
Date: Wed, 8 Jun 2016 10:41:19 -0700
Subject: [PATCH] Allow env disabling of the keyboard.  Show keyboard after
 short delay to avoid flickers

---
 plugins/openvr/src/OpenVrHelpers.cpp | 64 ++++++++++++++++++++--------
 1 file changed, 47 insertions(+), 17 deletions(-)

diff --git a/plugins/openvr/src/OpenVrHelpers.cpp b/plugins/openvr/src/OpenVrHelpers.cpp
index 6533371db8..1ff1c65ef8 100644
--- a/plugins/openvr/src/OpenVrHelpers.cpp
+++ b/plugins/openvr/src/OpenVrHelpers.cpp
@@ -99,19 +99,33 @@ static char textArray[8192];
 static QMetaObject::Connection _focusConnection, _focusTextConnection;
 extern bool _openVrDisplayActive;
 static vr::IVROverlay* _overlay { nullptr };
-static QObject* _focusObject { nullptr };
+static QObject* _keyboardFocusObject { nullptr };
 static QString _existingText;
 static Qt::InputMethodHints _currentHints;
 extern vr::TrackedDevicePose_t _trackedDevicePose[vr::k_unMaxTrackedDeviceCount];
+static bool _keyboardShown { false };
+static const uint32_t SHOW_KEYBOARD_DELAY_MS = 100;
 
 void showOpenVrKeyboard(bool show = true) {
-    if (_overlay) {
-        if (show) {
-            auto offscreenUi = DependencyManager::get<OffscreenUi>();
-            _focusObject = offscreenUi->getWindow()->focusObject();
+    if (!_overlay) {
+        return;
+    }
 
-            QInputMethodQueryEvent query(Qt::ImQueryInput | Qt::ImHints);
-            qApp->sendEvent(_focusObject, &query);
+    if (show) {
+        // To avoid flickering the keyboard when a text element is only briefly selected, 
+        // show the keyboard asynchrnously after a very short delay, but only after we check 
+        // that the current focus object is still one that is text enabled
+        QTimer::singleShot(SHOW_KEYBOARD_DELAY_MS, [] {
+            auto offscreenUi = DependencyManager::get<OffscreenUi>();
+            auto currentFocus = offscreenUi->getWindow()->focusObject();
+            QInputMethodQueryEvent query(Qt::ImEnabled | Qt::ImQueryInput | Qt::ImHints);
+            qApp->sendEvent(currentFocus, &query);
+            // Current focus isn't text enabled, bail early.
+            if (!query.value(Qt::ImEnabled).toBool()) {
+                return;
+            }
+            // We're going to show the keyboard now...
+            _keyboardFocusObject = currentFocus;
             _currentHints = Qt::InputMethodHints(query.value(Qt::ImHints).toUInt());
             vr::EGamepadTextInputMode inputMode = vr::k_EGamepadTextInputModeNormal;
             if (_currentHints & Qt::ImhHiddenText) {
@@ -123,17 +137,24 @@ void showOpenVrKeyboard(bool show = true) {
             }
             _existingText = query.value(Qt::ImSurroundingText).toString();
 
-            auto showKeyboardResult = _overlay->ShowKeyboard(inputMode, lineMode, "Keyboard", 1024, 
+            auto showKeyboardResult = _overlay->ShowKeyboard(inputMode, lineMode, "Keyboard", 1024,
                 _existingText.toLocal8Bit().toStdString().c_str(), false, 0);
 
-            mat4 headPose = toGlm(_trackedDevicePose[0].mDeviceToAbsoluteTracking);
-            mat4 keyboardTransform = glm::translate(headPose, vec3(0, -0.5, -1));
-            keyboardTransform = keyboardTransform * glm::rotate(mat4(), 3.14159f / 4.0f, vec3(-1, 0, 0));
-            auto keyboardTransformVr = toOpenVr(keyboardTransform);
-            _overlay->SetKeyboardTransformAbsolute(vr::ETrackingUniverseOrigin::TrackingUniverseStanding, &keyboardTransformVr);
-        } else {
-            _focusObject = nullptr;
+            if (vr::VROverlayError_None == showKeyboardResult) {
+                _keyboardShown = true;
+                // Try to position the keyboard slightly below where the user is looking.
+                mat4 headPose = toGlm(_trackedDevicePose[0].mDeviceToAbsoluteTracking);
+                mat4 keyboardTransform = glm::translate(headPose, vec3(0, -0.5, -1));
+                keyboardTransform = keyboardTransform * glm::rotate(mat4(), 3.14159f / 4.0f, vec3(-1, 0, 0));
+                auto keyboardTransformVr = toOpenVr(keyboardTransform);
+                _overlay->SetKeyboardTransformAbsolute(vr::ETrackingUniverseOrigin::TrackingUniverseStanding, &keyboardTransformVr);
+            }
+        });
+    } else {
+        _keyboardFocusObject = nullptr;
+        if (_keyboardShown) {
             _overlay->HideKeyboard();
+            _keyboardShown = false;
         }
     }
 }
@@ -147,7 +168,7 @@ void finishOpenVrKeyboardInput() {
     // ImhDialableCharactersOnly ImhEmailCharactersOnly  ImhUrlCharactersOnly  ImhLatinOnly
     QInputMethodEvent event(_existingText, QList<QInputMethodEvent::Attribute>());
     event.setCommitString(newText, 0, _existingText.size());
-    qApp->sendEvent(_focusObject, &event);
+    qApp->sendEvent(_keyboardFocusObject, &event);
     // Simulate an enter press on the top level window to trigger the action
     if (0 == (_currentHints & Qt::ImhMultiLine)) {
         qApp->sendEvent(offscreenUi->getWindow(), &QKeyEvent(QEvent::KeyPress, Qt::Key_Return, Qt::KeyboardModifiers(), QString("\n")));
@@ -155,12 +176,18 @@ void finishOpenVrKeyboardInput() {
     }
 }
 
+static const QString DEBUG_FLAG("HIFI_DISABLE_STEAM_VR_KEYBOARD");
+bool disableSteamVrKeyboard = QProcessEnvironment::systemEnvironment().contains(DEBUG_FLAG);
+
 void enableOpenVrKeyboard() {
+    if (disableSteamVrKeyboard) {
+        return;
+    }
     auto offscreenUi = DependencyManager::get<OffscreenUi>();
     _overlay = vr::VROverlay();
 
     _focusConnection = QObject::connect(offscreenUi->getWindow(), &QQuickWindow::focusObjectChanged, [](QObject* object) {
-        if (object != _focusObject && _overlay) {
+        if (object != _keyboardFocusObject) {
             showOpenVrKeyboard(false);
         }
     });
@@ -174,6 +201,9 @@ void enableOpenVrKeyboard() {
 
 
 void disableOpenVrKeyboard() {
+    if (disableSteamVrKeyboard) {
+        return;
+    }
     QObject::disconnect(_focusTextConnection);
     QObject::disconnect(_focusConnection);
 }