monitor_reconfig: Handle external monitors and add tests.

Makefile

Index: Makefile
diff --git a/Makefile b/Makefile
index d62f0f6e58be9c1e2059347900a03d3e9d35cc6f..3ef81f1b063d3fbdceed9a8c399157e9e3a2983d 100644
--- a/Makefile
+++ b/Makefile
@@ -7,21 +7,28 @@ CXXFLAGS ?= -Wall -Werror -g
 PKG_CONFIG ?= pkg-config
 
 LIBS = -lbase -lpthread -lrt
+TEST_LIBS = -lgtest -lgflags
 INCLUDE_DIRS = -I.. $(shell $(PKG_CONFIG) --cflags x11 xrandr)
 LIB_DIRS = $(shell $(PKG_CONFIG) --libs x11 xrandr)
 
 
 BIN=monitor_reconfigure
-OBJECTS=monitor_reconfigure_main.o
+OBJECTS=monitor_reconfigure_main.o resolution_selector.o
 
 .cc.o:
 	$(CXX) $(CXXFLAGS) $(INCLUDE_DIRS) -c $< -o $@
 
 $(BIN): $(OBJECTS)
 	$(CXX) $(CXXFLAGS) $(INCLUDE_DIRS) $(LIB_DIRS) $^ $(LIBS) $(LDFLAGS) \
-		-o $@
+	  -o $@
 
 all: $(BIN)
 
+test: resolution_selector_test
+
+resolution_selector_test: resolution_selector_test.cc resolution_selector.o
+	$(CXX) $(CXXFLAGS) $(INCLUDE_DIRS) $(LIB_DIRS) $^ \
+	  $(LIBS) $(TEST_LIBS) $(LDFLAGS) -o $@
+
 clean:
-	@rm -f $(BIN) $(OBJECTS)
+	@rm -f $(BIN) $(OBJECTS) resolution_selector_test