Merge pull request #748 from wesnoth/staging-event-handlers

Staging area for event handlers

src/events.cpp

@@ -34,6 +34,7 @@
 #include <utility>
 #include <vector>
 #include <algorithm>
+#include <iterator>
 #include <boost/thread.hpp>
 
 #define ERR_GEN LOG_STREAM(err, lg::general)
@@ -43,7 +44,10 @@ namespace events
 
 void context::add_handler(sdl_handler* ptr)
 {
-	handlers.push_back(ptr);
+	/* Add new handlers to the staging list initially.
+	This ensures that if an event handler adds more handlers, the new handlers
+	won't be called for the event that caused them to be added. */
+	staging_handlers.push_back(ptr);
 }
 
 bool context::remove_handler(sdl_handler* ptr)
@@ -68,7 +72,18 @@ bool context::remove_handler(sdl_handler* ptr)
 
 		if(i == handlers.end()) {
 			--depth;
-			return false;
+
+			// The handler may be in the staging area. Search it from there.
+			auto j = std::find(staging_handlers.begin(), staging_handlers.end(), ptr);
+			if (j != staging_handlers.end())
+			{
+				staging_handlers.erase(j);
+				return true;
+			}
+			else
+			{
+				return false;
+			}
 		}
 
 		if(i == focused_handler) {
@@ -131,6 +146,12 @@ void context::set_focus(const sdl_handler* ptr)
 	}
 }
 
+void context::add_staging_handlers()
+{
+	std::copy(staging_handlers.begin(), staging_handlers.end(), std::back_inserter(handlers));
+	staging_handlers.clear();
+}
+
 context::~context()
 {
 	for (sdl_handler* h : handlers)
@@ -445,6 +466,11 @@ void pump()
 	ev_end = events.end();
 
 	for(ev_it = events.begin(); ev_it != ev_end; ++ev_it){
+		for (context& c : event_contexts)
+		{
+			c.add_staging_handlers();
+		}
+
 		SDL_Event &event = *ev_it;
 		switch(event.type) {
 

src/events.hpp

@@ -41,7 +41,8 @@ class context
 public:
 	context() :
 		handlers(),
-		focused_handler(handlers.end())
+		focused_handler(handlers.end()),
+		staging_handlers()
 	{
 	}
 
@@ -53,9 +54,11 @@ public:
 	bool remove_handler(sdl_handler* ptr);
 	void cycle_focus();
 	void set_focus(const sdl_handler* ptr);
+	void add_staging_handlers();
 
 	handler_list handlers;
 	handler_list::iterator focused_handler;
+	std::vector<sdl_handler*> staging_handlers;
 };
 
 //any classes that derive from this class will automatically

src/widgets/textbox.cpp

@@ -30,20 +30,21 @@ static lg::log_domain log_display("display");
 
 namespace gui {
 
-textbox::textbox(CVideo &video, int width, const std::string& text, bool editable, size_t max_size, int font_size, double alpha, double alpha_focus, const bool auto_join) :
-	scrollarea(video, auto_join), max_size_(max_size), font_size_(font_size), text_(unicode_cast<ucs4::string>(text)),
-	cursor_(text_.size()), selstart_(-1), selend_(-1),
-	grabmouse_(false), text_pos_(0), editable_(editable),
-	show_cursor_(true), show_cursor_at_(0), text_image_(nullptr),
-	wrap_(false), line_height_(0), yscroll_(0), alpha_(alpha),
-	alpha_focus_(alpha_focus),
-	edit_target_(nullptr),
-	initially_pressed_keys_()
+textbox::textbox(CVideo &video, int width, const std::string& text, bool editable, size_t max_size, int font_size, double alpha, double alpha_focus, const bool auto_join)
+	   : scrollarea(video, auto_join), max_size_(max_size), font_size_(font_size), text_(unicode_cast<ucs4::string>(text)),
+	     cursor_(text_.size()), selstart_(-1), selend_(-1),
+	     grabmouse_(false), text_pos_(0), editable_(editable),
+	     show_cursor_(true), show_cursor_at_(0), text_image_(nullptr),
+	     wrap_(false), line_height_(0), yscroll_(0), alpha_(alpha),
+	     alpha_focus_(alpha_focus),
+	     edit_target_(nullptr)
+		,listening_(false)
 {
+	// static const SDL_Rect area = d.screen_area();
+	// const int height = font::draw_text(nullptr,area,font_size,font::NORMAL_COLOR,"ABCD",0,0).h;
 	set_measurements(width, font::get_max_height(font_size_));
 	set_scroll_rate(font::get_max_height(font_size_) / 2);
 	update_text_cache(true);
-	determine_initially_pressed_keys();
 }
 
 textbox::~textbox()
@@ -476,6 +477,8 @@ bool textbox::handle_key_down(const SDL_Event &event)
 	const int c = key.sym;
 	const int old_cursor = cursor_;
 
+	listening_ = true;
+
 	if(editable_) {
 		if(c == SDLK_LEFT && cursor_ > 0)
 			--cursor_;
@@ -595,12 +598,6 @@ bool textbox::handle_key_down(const SDL_Event &event)
 	return changed;
 }
 
-bool textbox::handle_key_up(const SDL_Event& event)
-{
-	initially_pressed_keys_.erase(static_cast<uint16_t>(event.key.keysym.scancode));
-	return false;
-}
-
 void textbox::handle_event(const SDL_Event& event, bool was_forwarded)
 {
 	if(!enabled())
@@ -682,14 +679,11 @@ void textbox::handle_event(const SDL_Event& event, bool was_forwarded)
 
 	const int old_cursor = cursor_;
 
-	if (event.type == SDL_TEXTINPUT && is_listening()) {
+	if (event.type == SDL_TEXTINPUT && listening_) {
 		changed = handle_text_input(event);
-	}
-	else if (event.type == SDL_KEYDOWN) {
-		changed = handle_key_down(event);
-	}
-	else if (event.type == SDL_KEYUP) {
-		changed = handle_key_up(event);
+	} else
+		if (event.type == SDL_KEYDOWN) {
+			changed = handle_key_down(event);
 	}
 	else {
 		if(event.type != SDL_KEYDOWN || (!was_forwarded && focus(&event) != true)) {
@@ -727,17 +721,4 @@ void textbox::set_edit_target(textbox* target)
 	edit_target_ = target;
 }
 
-void textbox::determine_initially_pressed_keys()
-{
-	int num_keys;
-	const uint8_t* keys = SDL_GetKeyboardState(&num_keys);
-	for (uint16_t i = 0u; i < static_cast<uint16_t>(num_keys); ++i)
-	{
-		if (keys[i] == 1u)
-		{
-			initially_pressed_keys_.insert(i);
-		}
-	}
-}
-
 } //end namespace gui

src/widgets/textbox.hpp

@@ -17,8 +17,6 @@
 
 #include "serialization/unicode.hpp"
 #include "font.hpp"
-#include <cstdint>
-#include <set>
 
 #include "scrollarea.hpp"
 
@@ -94,15 +92,11 @@ private:
 
 	textbox* edit_target_;
 
-	/* This set contains all the keys which were pressed when the textbox was created.
-	 * This is needed to block the textbox from receiving text input from a hotkey
-	 * that was used to spawn the textbox in the first place.
+	/* This boolean is used to filter out any TextInput events that are received without
+	 * the corresponding KeyPress events. This is needed to avoid a bug when creating a
+	 * textbox using a hotkey.
 	 * */
-	std::set<uint16_t> initially_pressed_keys_;
-
-	bool is_listening() const { return initially_pressed_keys_.empty(); }
-
-	void determine_initially_pressed_keys();
+	bool listening_;
 
 	void handle_event(const SDL_Event& event, bool was_forwarded);
 
@@ -123,7 +117,6 @@ private:
 	bool show_scrollbar() const;
 	bool handle_text_input(const SDL_Event& event);
 	bool handle_key_down(const SDL_Event &event);
-	bool handle_key_up(const SDL_Event &event);
 };
 
 }