From 97d0f78c43d16fbf73ea0438148a4da781c75600 Mon Sep 17 00:00:00 2001
From: Holger Schemel <info@artsoft.org>
Date: Thu, 27 Oct 2016 09:59:03 +0200
Subject: [PATCH] improved shifting up video display when activating screen
 keyboard (Android)

---
 src/events.c          |  5 +++++
 src/libgame/gadgets.c |  6 ++++--
 src/libgame/sdl.c     | 27 +++++++++++++++++++++++----
 src/libgame/system.c  | 19 ++++++++++++++++---
 src/libgame/system.h  |  7 ++++++-
 src/screens.c         |  2 +-
 6 files changed, 55 insertions(+), 11 deletions(-)

diff --git a/src/events.c b/src/events.c
index e197be5c..5bcdd5fb 100644
--- a/src/events.c
+++ b/src/events.c
@@ -412,6 +412,11 @@ void HandleButtonEvent(ButtonEvent *event)
 	event->x, event->y);
 #endif
 
+#if defined(HAS_SCREEN_KEYBOARD)
+  if (video.shifted_up)
+    event->y += video.shifted_up_pos;
+#endif
+
   motion_status = FALSE;
 
   if (event->type == EVENT_BUTTONPRESS)
diff --git a/src/libgame/gadgets.c b/src/libgame/gadgets.c
index 736f1465..98e46a5a 100644
--- a/src/libgame/gadgets.c
+++ b/src/libgame/gadgets.c
@@ -1709,7 +1709,8 @@ boolean HandleGadgets(int mx, int my, int button)
       if (gi->textinput.cursor_position != old_cursor_position)
 	DrawGadget(gi, DG_PRESSED, gi->direct_draw);
 
-      StartTextInput(gi->x, gi->y);
+      if (press_event)
+	StartTextInput(gi->x, gi->y, gi->width, gi->height);
     }
     else if (gi->type & GD_TYPE_TEXT_AREA && button != 0 && !motion_status)
     {
@@ -1725,7 +1726,8 @@ boolean HandleGadgets(int mx, int my, int button)
       if (gi->textarea.cursor_position != old_cursor_position)
 	DrawGadget(gi, DG_PRESSED, gi->direct_draw);
 
-      StartTextInput(gi->x, gi->y);
+      if (press_event)
+	StartTextInput(gi->x, gi->y, gi->width, gi->height);
     }
     else if (gi->type & GD_TYPE_SELECTBOX && gi->selectbox.open &&
 	     !keep_selectbox_open)
diff --git a/src/libgame/sdl.c b/src/libgame/sdl.c
index ba3b6ac4..7a108238 100644
--- a/src/libgame/sdl.c
+++ b/src/libgame/sdl.c
@@ -131,12 +131,31 @@ static void UpdateScreenExt(SDL_Rect *rect, boolean with_frame_delay)
 
   SDL_Rect *src_rect1 = NULL, *dst_rect1 = NULL;
   SDL_Rect *src_rect2 = NULL, *dst_rect2 = NULL;
-#if defined(HAS_SCREEN_KEYBOARD)
-  SDL_Rect src_rect_up = { 0, video.height / 2, video.width, video.height / 2 };
-  SDL_Rect dst_rect_up = { 0, 0,                video.width, video.height / 2 };
 
-  if (video.shifted_up)
+#if defined(HAS_SCREEN_KEYBOARD)
+  if (video.shifted_up || video.shifted_up_delay)
   {
+    int time_current = SDL_GetTicks();
+    int pos = video.shifted_up_pos;
+    int pos_last = video.shifted_up_pos_last;
+
+    if (!DelayReachedExt(&video.shifted_up_delay, video.shifted_up_delay_value,
+			 time_current))
+    {
+      int delay = time_current - video.shifted_up_delay;
+      int delay_value = video.shifted_up_delay_value;
+
+      pos = pos_last + (pos - pos_last) * delay / delay_value;
+    }
+    else
+    {
+      video.shifted_up_pos_last = pos;
+      video.shifted_up_delay = 0;
+    }
+
+    SDL_Rect src_rect_up = { 0, pos, video.width, video.height - pos };
+    SDL_Rect dst_rect_up = { 0, 0,   video.width, video.height - pos };
+
     if (video.screen_rendering_mode == SPECIAL_RENDERING_TARGET ||
 	video.screen_rendering_mode == SPECIAL_RENDERING_DOUBLE)
     {
diff --git a/src/libgame/system.c b/src/libgame/system.c
index df401b5a..7d85f617 100644
--- a/src/libgame/system.c
+++ b/src/libgame/system.c
@@ -387,6 +387,10 @@ void InitVideoBuffer(int width, int height, int depth, boolean fullscreen)
   video.frame_delay_value = GAME_FRAME_DELAY;
 
   video.shifted_up = FALSE;
+  video.shifted_up_pos = 0;
+  video.shifted_up_pos_last = 0;
+  video.shifted_up_delay = 0;
+  video.shifted_up_delay_value = ONE_SECOND_DELAY / 4;
 
   SDLInitVideoBuffer(fullscreen);
 
@@ -1513,14 +1517,18 @@ KeyMod GetKeyModStateFromEvents()
   return HandleKeyModState(KSYM_UNDEFINED, 0);
 }
 
-void StartTextInput(int x, int y)
+void StartTextInput(int x, int y, int width, int height)
 {
 #if defined(TARGET_SDL2)
   SDL_StartTextInput();
 
 #if defined(HAS_SCREEN_KEYBOARD)
-  if (y > video.height / 2)
+  if (y + height > SCREEN_KEYBOARD_POS(video.height))
+  {
+    video.shifted_up_pos = y + height - SCREEN_KEYBOARD_POS(video.height);
+    video.shifted_up_delay = SDL_GetTicks();
     video.shifted_up = TRUE;
+  }
 #endif
 #endif
 }
@@ -1531,7 +1539,12 @@ void StopTextInput()
   SDL_StopTextInput();
 
 #if defined(HAS_SCREEN_KEYBOARD)
-  video.shifted_up = FALSE;
+  if (video.shifted_up)
+  {
+    video.shifted_up_pos = 0;
+    video.shifted_up_delay = SDL_GetTicks();
+    video.shifted_up = FALSE;
+  }
 #endif
 #endif
 }
diff --git a/src/libgame/system.h b/src/libgame/system.h
index 009cbf81..b4e0df64 100644
--- a/src/libgame/system.h
+++ b/src/libgame/system.h
@@ -95,6 +95,7 @@
 /* values for screen keyboard on mobile devices */
 #if defined(PLATFORM_ANDROID)
 #define HAS_SCREEN_KEYBOARD
+#define SCREEN_KEYBOARD_POS(h)		((h) / 2)
 #endif
 
 
@@ -808,6 +809,10 @@ struct VideoSystemInfo
   unsigned int frame_delay_value;
 
   boolean shifted_up;
+  int shifted_up_pos;
+  int shifted_up_pos_last;
+  unsigned int shifted_up_delay;
+  unsigned int shifted_up_delay_value;
 
   boolean initialized;
 };
@@ -1496,7 +1501,7 @@ Key GetEventKey(KeyEvent *, boolean);
 KeyMod HandleKeyModState(Key, int);
 KeyMod GetKeyModState();
 KeyMod GetKeyModStateFromEvents();
-void StartTextInput(int, int);
+void StartTextInput(int, int, int, int);
 void StopTextInput();
 boolean CheckCloseWindowEvent(ClientMessageEvent *);
 
diff --git a/src/screens.c b/src/screens.c
index d38878c3..71f73cdb 100644
--- a/src/screens.c
+++ b/src/screens.c
@@ -3585,7 +3585,7 @@ void HandleTypeName(int newxpos, Key key)
 
     xpos = newxpos;
 
-    StartTextInput(startx, starty);
+    StartTextInput(startx, starty, pos->width, pos->height);
   }
   else if (is_valid_key_char && xpos < MAX_PLAYER_NAME_LEN)
   {
-- 
2.34.1