started transition tool (#109)

panels/timeline.cpp

@@ -89,6 +89,7 @@ Timeline::Timeline(QWidget *parent) :
 	tool_buttons.append(ui->toolSlipButton);
 	tool_buttons.append(ui->toolRollingButton);
     tool_buttons.append(ui->toolSlideButton);
+	tool_buttons.append(ui->toolTransitionButton);
 
 	ui->toolArrowButton->click();
 
@@ -1042,7 +1043,7 @@ void Timeline::deselect() {
 }
 
 long getFrameFromScreenPoint(double zoom, int x) {
-    long f = qRound((float) x / zoom);
+	long f = qCeil((float) x / zoom);
 	if (f < 0) {
 		return 0;
 	}
@@ -1050,7 +1051,7 @@ long getFrameFromScreenPoint(double zoom, int x) {
 }
 
 int getScreenPointFromFrame(double zoom, long frame) {
-    return (int) qRound(frame*zoom);
+	return (int) qFloor(frame*zoom);
 }
 
 long Timeline::getTimelineFrameFromScreenPoint(int x) {
@@ -1167,3 +1168,10 @@ void Timeline::on_recordButton_clicked() {
 		creating_object = ADD_OBJ_AUDIO;
 	}
 }
+
+void Timeline::on_toolTransitionButton_clicked() {
+	decheck_tool_buttons(sender());
+	ui->timeline_area->setCursor(Qt::CrossCursor);
+	tool = TIMELINE_TOOL_TRANSITION;
+	creating = false;
+}

panels/timeline.h

@@ -201,6 +201,8 @@ private slots:
 
 	void on_recordButton_clicked();
 
+	void on_toolTransitionButton_clicked();
+
 private:
 	QVector<QPushButton*> tool_buttons;
 	void decheck_tool_buttons(QObject* sender);

panels/timeline.ui

@@ -194,6 +194,25 @@
          </property>
         </widget>
        </item>
+       <item>
+        <widget class="QPushButton" name="toolTransitionButton">
+         <property name="toolTip">
+          <string>Transition Tool (T)</string>
+         </property>
+         <property name="text">
+          <string/>
+         </property>
+         <property name="icon">
+          <iconset>
+           <normalon>:/icons/transition-tool.png</normalon>
+           <disabledon>:/icons/transition-tool-disabled.png</disabledon>
+          </iconset>
+         </property>
+         <property name="checkable">
+          <bool>true</bool>
+         </property>
+        </widget>
+       </item>
        <item>
         <widget class="QPushButton" name="snappingButton">
          <property name="text">