From 12d7b10c10fd3636a7cb61909f12e4e10e8fe73d Mon Sep 17 00:00:00 2001
From: Mike Erwin <significant.bit@gmail.com>
Date: Thu, 8 Jul 2010 01:53:36 +0000
Subject: [PATCH] added filtered event dispatch for lo-fi mouse/pen input

---
 intern/ghost/intern/GHOST_EventManager.cpp | 71 +++++++++++++++++++++-
 intern/ghost/intern/GHOST_EventManager.h   |  8 +++
 intern/ghost/intern/GHOST_System.cpp       | 10 ++-
 intern/ghost/intern/GHOST_System.h         |  1 +
 4 files changed, 82 insertions(+), 8 deletions(-)

diff --git a/intern/ghost/intern/GHOST_EventManager.cpp b/intern/ghost/intern/GHOST_EventManager.cpp
index 0eeb2245cd0..8f5b5e74339 100644
--- a/intern/ghost/intern/GHOST_EventManager.cpp
+++ b/intern/ghost/intern/GHOST_EventManager.cpp
@@ -38,6 +38,10 @@
 #include <algorithm>
 #include "GHOST_Debug.h"
 
+// for testing lo-fi
+#include "GHOST_EventPrinter.h"
+#include <iostream>
+using namespace std;
 
 GHOST_EventManager::GHOST_EventManager()
 {
@@ -81,7 +85,7 @@ GHOST_TUns32 GHOST_EventManager::getNumEvents(GHOST_TEventType type)
 GHOST_IEvent* GHOST_EventManager::peekEvent()
 {
 	GHOST_IEvent* event = 0;
-	if (m_events.size() > 0) {
+	if (!m_events.empty()) {
 		event = m_events.back();
 	}
 	return event;
@@ -104,6 +108,24 @@ GHOST_TSuccess GHOST_EventManager::pushEvent(GHOST_IEvent* event)
 
 
 bool GHOST_EventManager::dispatchEvent(GHOST_IEvent* event)
+{
+	// [mce] this variant switches the "handled" flag to work as described in the header
+	//       it also stops after the first consumer has handled the event
+	bool handled = false;
+	if (event) {
+		TConsumerVector::iterator iter;
+		for (iter = m_consumers.begin(); iter != m_consumers.end(); iter++) {
+			if ((*iter)->processEvent(event)) {
+				handled = true;
+				// break;
+			}
+		}
+	}
+	return handled;
+}
+
+#if 0 // disable to test a variant
+bool GHOST_EventManager::dispatchEvent_original(GHOST_IEvent* event)
 {
 	bool handled;
 	if (event) {
@@ -120,7 +142,7 @@ bool GHOST_EventManager::dispatchEvent(GHOST_IEvent* event)
 	}
 	return handled;
 }
-
+#endif
 
 bool GHOST_EventManager::dispatchEvent()
 {
@@ -152,6 +174,51 @@ bool GHOST_EventManager::dispatchEvents()
 }
 
 
+bool GHOST_EventManager::dispatchEvents_lo_fi()
+{
+	if (m_events.empty())
+		return false;
+
+	bool allHandled = true;
+	GHOST_IEvent* cursorMove = NULL;
+	GHOST_IEvent* event = NULL;
+
+	GHOST_EventPrinter printer;
+
+	// when Pen gets its own event type, track it alongside mouse moves
+	// they probably won't both be active, but you never know
+
+	cout << "\n--- lo-fi dispatch ---";
+	cout << "\ndiscard:";
+	while ((event = popEvent()) != NULL) {
+		if (event->getType() == GHOST_kEventCursorMove) {
+			// just a simple (x,y) pair, nothing much to adjust
+			// discard the older event and keep the latest
+			if (cursorMove) {
+				printer.processEvent(cursorMove);
+				delete cursorMove;
+			}
+			cursorMove = event;
+		}
+		else // not a cursor move event
+			if (!dispatchEvent(event))
+				allHandled = false;
+	}
+		
+	// finally dispatch the single cursor update
+	if (cursorMove) {
+		cout << "\nsend:";
+		printer.processEvent(cursorMove);
+		if (!dispatchEvent(cursorMove))
+			allHandled = false;
+	}
+
+	cout << endl;
+
+	return allHandled;
+}
+
+
 GHOST_TSuccess GHOST_EventManager::addConsumer(GHOST_IEventConsumer* consumer)
 {
 	GHOST_TSuccess success;
diff --git a/intern/ghost/intern/GHOST_EventManager.h b/intern/ghost/intern/GHOST_EventManager.h
index 40ba133e8fd..5071adb1bd4 100644
--- a/intern/ghost/intern/GHOST_EventManager.h
+++ b/intern/ghost/intern/GHOST_EventManager.h
@@ -108,6 +108,14 @@ public:
 	 */
 	virtual bool dispatchEvents();
 
+	/**
+	 * Dispatches most events on the stack, consolidating cursor moves into a single move.
+	 * The event stack will be empty afterwards.
+	 * @return Indicates whether all events were handled by some consumer.
+	 */
+	bool dispatchEvents_lo_fi();
+
+
 	/**
 	 * Adds a consumer to the list of event consumers.
 	 * @param consumer The consumer added to the list.
diff --git a/intern/ghost/intern/GHOST_System.cpp b/intern/ghost/intern/GHOST_System.cpp
index 3cd3528eeb6..25b55345d46 100644
--- a/intern/ghost/intern/GHOST_System.cpp
+++ b/intern/ghost/intern/GHOST_System.cpp
@@ -198,7 +198,10 @@ bool GHOST_System::dispatchEvents()
 {
 	bool handled;
 	if (m_eventManager) {
-		handled = m_eventManager->dispatchEvents();
+		if (m_input_fidelity_hint == LO_FI)
+			handled = m_eventManager->dispatchEvents_lo_fi();
+		else
+			handled = m_eventManager->dispatchEvents();
 	}
 	else {
 		handled = false;
@@ -283,11 +286,6 @@ GHOST_TSuccess GHOST_System::init()
 	m_eventManager = new GHOST_EventManager ();
     m_ndofManager = new GHOST_NDOFManager();
 
-#if 0
-	if(m_ndofManager)
-		printf("ndof manager \n");
-#endif
-	
 #ifdef GHOST_DEBUG
 	if (m_eventManager) {
 		m_eventPrinter = new GHOST_EventPrinter();
diff --git a/intern/ghost/intern/GHOST_System.h b/intern/ghost/intern/GHOST_System.h
index 6f570b33079..1aeb8597573 100644
--- a/intern/ghost/intern/GHOST_System.h
+++ b/intern/ghost/intern/GHOST_System.h
@@ -39,6 +39,7 @@
 #include "GHOST_Buttons.h"
 #include "GHOST_ModifierKeys.h"
 #include "GHOST_EventManager.h"
+
 #ifdef GHOST_DEBUG
 #include "GHOST_EventPrinter.h"
 #endif // GHOST_DEBUG