Add parse_line method to decouple buffer from gesture handler (#50)

lib/gesture/swipe_gesture.cpp

@@ -20,7 +20,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include <iostream> // std::cout, std::endl
-#include "xdo_gesture.h"
+#include <string> // std::stoi, std::stof
+#include <regex> // std::regex, std::regex_match, std::cmatch
+#include "swipe_gesture.h"
 
 extern "C"
 {
@@ -127,6 +129,65 @@ namespace comfortable_swipe::gesture
     void swipe_gesture::end()
     { }
 
+    /**
+     * Dispatches begin/update/end depending on the regex pattern provided by this class.
+     *
+     * @param line  the line from libinput debug-events to parse
+     * @return true if begin/update/end was dispatched
+     */
+    bool swipe_gesture::parse_line(const char * line)
+    {
+
+        // prepare regex matchers (will only load at most once)
+        static const std::regex gesture_swipe_begin(swipe_gesture::GESTURE_BEGIN_REGEX_PATTERN);
+        static const std::regex gesture_swipe_update(swipe_gesture::GESTURE_UPDATE_REGEX_PATTERN);
+        static const std::regex gesture_swipe_end(swipe_gesture::GESTURE_END_REGEX_PATTERN);
+
+        // prepare holder for regex matches
+        static std::cmatch matches;
+
+        if (this->flag_swiping)
+        {
+            // currently swiping
+            if (std::regex_match(line, matches, gesture_swipe_update) != 0)
+            {
+                // assign necessary variables for swipe update
+                this->fingers = std::stoi(matches[1]);
+                this->dx = std::stof(matches[2]);
+                this->dy = std::stof(matches[3]);
+                this->udx = std::stof(matches[4]);
+                this->udy = std::stof(matches[5]);
+                // dispatch update
+                this->update();
+                return true;
+            }
+            else if (std::regex_match(line, matches, gesture_swipe_end) != 0)
+            {
+                // assign necessary variables for swipe end
+                this->flag_swiping = false;
+                this->fingers = std::stoi(matches[1]);
+                // dispatch end
+                this->end();
+                return true;
+            }
+        }
+        else
+        {
+            // not swiping, check if swipe will begin
+            if (std::regex_match(line, matches, gesture_swipe_begin) != 0)
+            {
+                // assign necessary variables for swipe begin
+                this->flag_swiping = true;
+                this->fingers = std::stoi(matches[1]);
+                // dispatch begin
+                this->begin();
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     /* STATICS DEFINITIONS */
     const int swipe_gesture::MSK_THREE_FINGERS = 0;
     const int swipe_gesture::MSK_FOUR_FINGERS = 1;

lib/gesture/swipe_gesture.h

@@ -52,6 +52,7 @@ namespace comfortable_swipe::gesture
         void begin() override;
         void update() override;
         void end() override;
+        bool parse_line(const char *) override;
 
     protected:
         // location of mouse
@@ -62,6 +63,9 @@ namespace comfortable_swipe::gesture
         int previous_gesture;
         const char ** commands;
 
+        // optimization flag for checking if GESTURE_SWIPE_BEGIN was dispatched
+        bool flag_swiping;
+
     public:
         // static constants
         static const int MSK_THREE_FINGERS;

lib/gesture/xdo_gesture.h

@@ -45,6 +45,7 @@ namespace comfortable_swipe
             virtual void begin() = 0;
             virtual void update() = 0;
             virtual void end() = 0;
+            virtual bool parse_line(const char *) = 0;
         };
     }
 }

lib/service/buffer.cpp

@@ -19,9 +19,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <string> // std::stoi, std::stof
 #include <cstdio> // std::fgets_unlocked, stdin
-#include <regex> // std::regex, std::regex_match, std::cmatch
 #include "../index.hpp"
 
 /**
@@ -34,13 +32,8 @@ namespace comfortable_swipe::service
         // read config file
         auto config = comfortable_swipe::util::read_config_file(comfortable_swipe::util::conf_filename());
 
-        // pre-compile regex patterns
-        static const std::regex gesture_swipe_begin(comfortable_swipe::gesture::swipe_gesture::GESTURE_BEGIN_REGEX_PATTERN);
-        static const std::regex gesture_swipe_update(comfortable_swipe::gesture::swipe_gesture::GESTURE_UPDATE_REGEX_PATTERN);
-        static const std::regex gesture_swipe_end(comfortable_swipe::gesture::swipe_gesture::GESTURE_END_REGEX_PATTERN);
-
         // initialize swipe gesture handler
-        comfortable_swipe::gesture::swipe_gesture swipe
+        comfortable_swipe::gesture::swipe_gesture swipe_gesture_handler
         (
             config.count("threshold") ? std::stof(config["threshold"]) : 0.0,
             config["left3"].c_str(),
@@ -56,47 +49,12 @@ namespace comfortable_swipe::service
         // prepare data containers
         static const int MAX_LINE_LENGTH = 256;
         static char data[MAX_LINE_LENGTH];
-        static std::cmatch matches;
-
-        // optimization flag for checking if GESTURE_SWIPE_BEGIN was dispatched
-        bool flag_swiping = false;
 
         // start reading lines from input one by one
         while (fgets_unlocked(data, MAX_LINE_LENGTH, stdin) != NULL)
         {
-            if (flag_swiping)
+            // attempt to parse swipe gestures
-            {
+            swipe_gesture_handler.parse_line(data);
-                // currently swiping
-                if (std::regex_match(data, matches, gesture_swipe_update) != 0)
-                {
-                    // update swipe
-                    swipe.fingers = std::stoi(matches[1]);
-                    swipe.dx = std::stof(matches[2]);
-                    swipe.dy = std::stof(matches[3]);
-                    swipe.udx = std::stof(matches[4]);
-                    swipe.udy = std::stof(matches[5]);
-                    swipe.update();
-                }
-                else if (std::regex_match(data, matches, gesture_swipe_end) != 0)
-                {
-                    // end swipe
-                    flag_swiping = false;
-                    swipe.fingers = std::stoi(matches[1]);
-                    swipe.end();
-                }
-            }
-            else /* !flag_swiping */
-            {
-                // not swiping, check if swipe will begin
-                if (std::regex_match(data, matches, gesture_swipe_begin) != 0)
-                {
-                    // begin swipe
-                    flag_swiping = true;
-                    swipe.fingers = std::stoi(matches[1]);
-                    swipe.begin();
-                }
-            }
-            
         }
     }
 }