Add workaround for fix alt-tab issue in SDL2.

Also add option to enable/disable this workaround.

13 files changed, 130 insertions, 10 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4049b940c..1c10028db 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1164,6 +1164,7 @@ SET(SRCS
     input/inputmanager.cpp
     input/inputmanager.h
     enums/input/inputtype.h
+    enums/input/keyboardfocus.h
     enums/input/keyvalue.h
     events/inputevent.h
     input/joystick.cpp
diff --git a/src/Makefile.am b/src/Makefile.am
index c82a336e7..36b43c5ef 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -719,6 +719,7 @@ BASE_SRC += client.h \
 	      input/inputmanager.cpp \
 	      input/inputmanager.h \
 	      enums/input/inputtype.h \
+	      enums/input/keyboardfocus.h \
 	      enums/input/keyvalue.h \
 	      input/joystick.cpp \
 	      input/joystick.h \
diff --git a/src/defaults.cpp b/src/defaults.cpp
index e3b1f91c6..5df7ab80e 100644
--- a/src/defaults.cpp
+++ b/src/defaults.cpp
@@ -414,6 +414,7 @@ void setConfigDefaults(Configuration &cfg)
     AddDEF("openglContext", false);
     AddDEF("allowMoveByMouse", true);
     AddDEF("enableDSA", true);
+    AddDEF("blockAltTab", true);
 }
 
 void setConfigDefaults2(Configuration &cfg)
diff --git a/src/enums/input/keyboardfocus.h b/src/enums/input/keyboardfocus.h
new file mode 100644
index 000000000..9b80f7f20
--- /dev/null
+++ b/src/enums/input/keyboardfocus.h
@@ -0,0 +1,34 @@
+/*
+ *  The ManaPlus Client
+ *  Copyright (C) 2012-2017  The ManaPlus Developers
+ *
+ *  This file is part of The ManaPlus Client.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef ENUMS_INPUT_KEYBOARDFOCUS_H
+#define ENUMS_INPUT_KEYBOARDFOCUS_H
+
+#include "enums/simpletypes/enumdefines.h"
+
+enumStart(KeyboardFocus)
+{
+    Unfocused = 0,
+    Focused   = 1,
+    Focused2  = 2
+}
+enumEnd(KeyboardFocus);
+
+#endif  // ENUMS_INPUT_KEYBOARDFOCUS_H
diff --git a/src/eventsmanager.cpp b/src/eventsmanager.cpp
index 76fe054fa..143937fe1 100644
--- a/src/eventsmanager.cpp
+++ b/src/eventsmanager.cpp
@@ -513,10 +513,16 @@ void EventsManager::handleSDL2WindowEvent(const SDL_Event &event)
             settings.mouseFocused = false;
             break;
         case SDL_WINDOWEVENT_FOCUS_GAINED:
-            settings.inputFocused = true;
+            settings.inputFocused = KeyboardFocus::Focused;
             break;
+#if SDL_VERSION_ATLEAST(2, 0, 5)
+        case SDL_WINDOWEVENT_TAKE_FOCUS:
+            settings.inputFocused = KeyboardFocus::Focused2;
+            break;
+#endif  // SDL_VERSION_ATLEAST(2, 0, 5)
+
         case SDL_WINDOWEVENT_FOCUS_LOST:
-            settings.inputFocused = false;
+            settings.inputFocused = KeyboardFocus::Unfocused;
             break;
         case SDL_WINDOWEVENT_MINIMIZED:
             WindowManager::setIsMinimized(true);
@@ -624,7 +630,10 @@ void EventsManager::handleActive(const SDL_Event &event)
 #endif  // DYECMD
 
     if ((event.active.state & SDL_APPINPUTFOCUS) != 0)
-        settings.inputFocused = (event.active.gain != 0u);
+    {
+        settings.inputFocused = (event.active.gain != 0u) ?
+            KeyboardFocus::Focused : KeyboardFocus::Unfocused;
+    }
     if ((event.active.state & SDL_APPMOUSEFOCUS) != 0)
         settings.mouseFocused = (event.active.gain != 0u);
 #ifndef DYECMD
diff --git a/src/game.cpp b/src/game.cpp
index 7a66c0b19..ad819230b 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -1002,10 +1002,15 @@ void Game::updateFrameRate(int fpsLimit)
     {
         if (settings.awayMode)
         {
-            if (settings.inputFocused || settings.mouseFocused)
+            if (settings.inputFocused != KeyboardFocus::Unfocused ||
+                settings.mouseFocused)
+            {
                 fpsLimit = config.getIntValue("fpslimit");
+            }
             else
+            {
                 fpsLimit = config.getIntValue("altfpslimit");
+            }
         }
         else
         {
diff --git a/src/gui/widgets/tabs/chat/chattab.cpp b/src/gui/widgets/tabs/chat/chattab.cpp
index ae75f9981..e4f6d751a 100644
--- a/src/gui/widgets/tabs/chat/chattab.cpp
+++ b/src/gui/widgets/tabs/chat/chattab.cpp
@@ -312,7 +312,8 @@ void ChatTab::chatLog(std::string line,
             return;
 
         const bool notFocused = WindowManager::getIsMinimized() ||
-            (!settings.mouseFocused && !settings.inputFocused);
+            (!settings.mouseFocused &&
+            settings.inputFocused == KeyboardFocus::Unfocused);
 
         if (this != tabArea->getSelectedTab() || notFocused)
         {
diff --git a/src/gui/widgets/tabs/setup_other.cpp b/src/gui/widgets/tabs/setup_other.cpp
index 413b93a7f..e608d27e1 100644
--- a/src/gui/widgets/tabs/setup_other.cpp
+++ b/src/gui/widgets/tabs/setup_other.cpp
@@ -332,6 +332,13 @@ Setup_Other::Setup_Other(const Widget2 *const widget) :
     new SetupItemIntTextField(_("Custom repeat interval"), "",
         "repeateInterval2", this, "repeateInterval2Event", 0, 10000);
 
+#ifdef USE_SDL2
+    // TRANSLATORS: settings option
+    new SetupItemCheckBox(_("Enable alt-tab workaround"), "",
+        "blockAltTab", this, "blockAltTabEvent");
+#endif  // USE_SDL2
+
+
     // TRANSLATORS: settings group
     new SetupItemLabel(_("Windows"), "", this);
 
diff --git a/src/input/inputmanager.cpp b/src/input/inputmanager.cpp
index dbe82d5da..42a4e3b25 100644
--- a/src/input/inputmanager.cpp
+++ b/src/input/inputmanager.cpp
@@ -594,6 +594,14 @@ bool InputManager::handleEvent(const SDL_Event &restrict event) restrict2
     {
         case SDL_KEYDOWN:
         {
+#ifdef USE_SDL2
+            if (keyboard.ignoreKey(event))
+            {
+                BLOCK_END("InputManager::handleEvent")
+                return true;
+            }
+#endif  // USE_SDL2
+
             keyboard.refreshActiveKeys();
             updateConditionMask();
             if (handleAssignKey(event, InputType::KEYBOARD))
@@ -620,6 +628,14 @@ bool InputManager::handleEvent(const SDL_Event &restrict event) restrict2
         }
         case SDL_KEYUP:
         {
+#ifdef USE_SDL2
+            if (keyboard.ignoreKey(event))
+            {
+                BLOCK_END("InputManager::handleEvent")
+                return true;
+            }
+#endif  // USE_SDL2
+
             keyboard.refreshActiveKeys();
             updateConditionMask();
             keyboard.handleDeActicateKey(event);
diff --git a/src/input/joystick.cpp b/src/input/joystick.cpp
index 1e53af5b1..10ed33924 100644
--- a/src/input/joystick.cpp
+++ b/src/input/joystick.cpp
@@ -180,7 +180,8 @@ void Joystick::logic()
 
     mDirection = 0;
 
-    if (mUseInactive || settings.inputFocused)
+    if (mUseInactive ||
+        settings.inputFocused != KeyboardFocus::Unfocused)
     {
         // X-Axis
         int position = SDL_JoystickGetAxis(mJoystick, 0);
@@ -350,7 +351,8 @@ bool Joystick::validate() const
     if (mCalibrating || !mEnabled || !mCalibrated)
         return false;
 
-    return mUseInactive || settings.inputFocused;
+    return mUseInactive ||
+        settings.inputFocused != KeyboardFocus::Unfocused;
 }
 
 void Joystick::handleRepeat(const int time)
diff --git a/src/input/keyboardconfig.cpp b/src/input/keyboardconfig.cpp
index 1ce317db7..e90d126a5 100644
--- a/src/input/keyboardconfig.cpp
+++ b/src/input/keyboardconfig.cpp
@@ -23,6 +23,9 @@
 #include "input/keyboardconfig.h"
 
 #include "configuration.h"
+#ifdef USE_SDL2
+#include "settings.h"
+#endif  // USE_SDL2
 
 #include "input/inputmanager.h"
 
@@ -42,7 +45,8 @@ KeyboardConfig::KeyboardConfig() :
     mRepeatTime(0),
     mKeyToAction(),
     mKeyToId(),
-    mKeyTimeMap()
+    mKeyTimeMap(),
+    mBlockAltTab(true)
 {
 }
 
@@ -52,6 +56,7 @@ void KeyboardConfig::init()
     delete [] mActiveKeys2;
     mActiveKeys2 = new uint8_t[500];
     mRepeatTime = config.getIntValue("repeateInterval2") / 10;
+    mBlockAltTab = config.getBoolValue("blockAltTab");
 }
 
 void KeyboardConfig::deinit()
@@ -270,3 +275,33 @@ void KeyboardConfig::resetRepeat(const int key)
     if (it != mKeyTimeMap.end())
         (*it).second = tick_time;
 }
+
+#ifdef USE_SDL2
+
+bool KeyboardConfig::ignoreKey(const SDL_Event &restrict event)
+{
+    if (!mBlockAltTab ||
+        mActiveKeys == nullptr)
+    {
+        return false;
+    }
+    const int key = event.key.keysym.scancode;
+    if (key == SDL_SCANCODE_TAB)
+    {
+#if SDL_VERSION_ATLEAST(2, 0, 5)
+        // SDL_WINDOWEVENT_TAKE_FOCUS not triggered after focus restored
+        if (settings.inputFocused != KeyboardFocus::Focused2)
+            return true;
+#endif // SDL_VERSION_ATLEAST(2, 0, 5)
+
+        if (mActiveKeys[SDL_SCANCODE_LALT] != 0)
+            return true;
+    }
+    else if (key == SDL_SCANCODE_LALT)
+    {
+        if (mActiveKeys[SDL_SCANCODE_TAB] != 0)
+            return true;
+    }
+    return false;
+}
+#endif  // USE_SDL2
diff --git a/src/input/keyboardconfig.h b/src/input/keyboardconfig.h
index 1759e4bb9..ef3f056b7 100644
--- a/src/input/keyboardconfig.h
+++ b/src/input/keyboardconfig.h
@@ -129,6 +129,10 @@ class KeyboardConfig final
 
         void resetRepeat(const int key);
 
+#ifdef USE_SDL2
+        bool ignoreKey(const SDL_Event &restrict event) A_WARN_UNUSED;
+#endif  // USE_SDL2
+
     private:
         bool mEnabled;                   /**< Flag to respond to key input */
 
@@ -143,6 +147,8 @@ class KeyboardConfig final
         KeyToIdMap mKeyToId;
 
         KeyTimeMap mKeyTimeMap;
+
+        bool mBlockAltTab;
 };
 
 extern KeyboardConfig keyboard;
diff --git a/src/settings.h b/src/settings.h
index 308da0202..1a165ad99 100644
--- a/src/settings.h
+++ b/src/settings.h
@@ -25,6 +25,8 @@
 
 #include "enums/emotetype.h"
 
+#include "enums/input/keyboardfocus.h"
+
 #include "enums/resources/map/maptype.h"
 
 #include "utils/vector.h"
@@ -82,7 +84,7 @@ class Settings final
             emoteType(EmoteType::Player),
             persistentIp(true),
             limitFps(false),
-            inputFocused(true),
+            inputFocused(KeyboardFocus::Focused),
             mouseFocused(true),
             disableGameModifiers(false),
             awayMode(false),
@@ -147,7 +149,7 @@ class Settings final
         EmoteTypeT emoteType;
         bool persistentIp;
         bool limitFps;
-        bool inputFocused;
+        KeyboardFocusT inputFocused;
         bool mouseFocused;
         bool disableGameModifiers;
         bool awayMode;