Add tooltip for pad

Display the pad caps when the mouse is over an element's pad.

src/GraphDisplay.cpp

@@ -24,6 +24,33 @@ GraphDisplay::GraphDisplay(QWidget *parent, Qt::WindowFlags f):
 QWidget(parent, f)
 {
 	setFocusPolicy(Qt::WheelFocus);
+	setMouseTracking(true);
+}
+
+ElementInfo* GraphDisplay::getElement(std::size_t elementId)
+{
+	ElementInfo* element = NULL;
+	std::size_t i=0;
+	for(; i<m_info.size(); i++)
+	{
+		if(m_info[i].m_id == elementId) {
+			element = &m_info[i];
+			break;
+		}
+	}
+	return element;
+}
+
+PadInfo* GraphDisplay::getPad(ElementInfo* element, std::size_t padId)
+{
+  PadInfo* pad = NULL;
+  std::size_t j=0;
+  for(; j<element->m_pads.size(); j++)
+	  if(element->m_pads[j].m_id == padId) {
+	      pad = &element->m_pads[j];
+	      break;
+	  }
+  return pad;
 }
 
 void GraphDisplay::updateDisplayInfoIds()
@@ -457,6 +484,18 @@ void GraphDisplay::mouseMoveEvent(QMouseEvent *event)
 	{
 		m_moveInfo.m_position = event -> pos();
 		repaint();
+	} else {
+	    std::size_t elementId, padId;
+	    getIdByPosition(event -> pos(), elementId, padId);
+	    if (padId != ((size_t)-1)) {
+		ElementInfo* element = getElement(elementId);
+		PadInfo* pad = getPad(element, padId);
+		QString caps = m_pGraph->getPadCaps(element,pad,PAD_CAPS_ALL,true);
+		setToolTip(caps);
+	    }
+	    else
+	      setToolTip("");
+
 	}
 }
 

src/GraphDisplay.h

@@ -79,6 +79,9 @@ private:
 	void disconnect(std::size_t elementId, std::size_t padId);
 	void requestPad(std::size_t elementId);
 
+	ElementInfo* getElement(std::size_t elementId);
+	PadInfo* getPad(ElementInfo* element, std::size_t padId);
+
 	std::vector <ElementInfo>            m_info;
 	std::vector <ElementDisplayInfo>     m_displayInfo;
 

src/GraphManager.cpp

@@ -8,6 +8,19 @@
 
 #include "CustomSettings.h"
 
+#define MAX_STR_CAPS_SIZE 150
+gchar* get_str_caps_limited(gchar* str)
+{
+  gchar* result;
+  if(strlen(str) > MAX_STR_CAPS_SIZE) {
+      result = g_strndup(str, MAX_STR_CAPS_SIZE);
+      for(int i = strlen(result)-1;i > strlen(result)-4 ;i--)
+	result[i] = '.';
+  } else
+    result = g_strdup(str);
+  return result;
+}
+
 GraphManager::GraphManager()
 {
 	m_pGraph = gst_pipeline_new ("pipeline");
@@ -19,6 +32,65 @@ GraphManager::~GraphManager()
 
 }
 
+QString GraphManager::getPadCaps(ElementInfo* elementInfo, PadInfo* padInfo, ePadCapsSubset subset,  bool afTruncated)
+{
+	QString padCaps = "";
+	if(!elementInfo || !padInfo)
+	  return padCaps;
+
+	GstElement *element = gst_bin_get_by_name (GST_BIN(m_pGraph), elementInfo->m_name.c_str());
+
+	if(!element)
+		return padCaps;
+	GstPad *pad = gst_element_get_static_pad(GST_ELEMENT(element), padInfo->m_name.c_str());
+	if(!pad) {
+	    gst_object_unref(element);
+	    return padCaps;
+	}
+	GstCaps *caps;
+	switch(subset)
+	{
+	  case PAD_CAPS_ALLOWED:
+	    caps =  gst_pad_get_allowed_caps(pad);
+	    break;
+	  case PAD_CAPS_NEGOCIATED:
+#if GST_VERSION_MAJOR >= 1
+	caps = gst_pad_get_current_caps(pad, NULL);
+#else
+	caps = gst_pad_get_negotiated_caps(pad);
+#endif
+	  break;
+	  case PAD_CAPS_ALL:
+	  default:
+#if GST_VERSION_MAJOR >= 1
+	    caps = gst_pad_query_caps(pad, NULL);
+#else
+	    caps = gst_pad_get_caps(pad);
+#endif
+	}
+#if GST_VERSION_MAJOR >= 1
+	caps = gst_pad_query_caps(pad, NULL);
+#else
+	caps = gst_pad_get_caps(pad);
+#endif
+	if(caps) {
+	    gchar* str = gst_caps_to_string(caps);
+	    if (afTruncated) {
+		    gchar* str_limited = get_str_caps_limited(str);
+		    g_free(str);
+		    padCaps = str_limited;
+		    g_free(str_limited);
+	    } else {
+		 padCaps = str;
+		 g_free(str);
+	    }
+
+	}
+
+	gst_object_unref(element);
+	gst_object_unref (pad);
+	return padCaps;
+}
 
 bool GraphManager::AddPlugin(const char *plugin, const char *name)
 {

src/GraphManager.h

@@ -6,6 +6,14 @@
 #include <string>
 #include <vector>
 
+class QString;
+
+enum ePadCapsSubset {
+  PAD_CAPS_ALLOWED = 0,
+  PAD_CAPS_NEGOCIATED,
+  PAD_CAPS_ALL
+};
+
 struct PadInfo
 {
 	public:
@@ -94,6 +102,8 @@ public:
 	bool Pause();
 	bool Stop();
 
+	QString getPadCaps(ElementInfo* elementInfo, PadInfo* padInfo, ePadCapsSubset subset, bool afTruncated = false);
+
 	GstElement       *m_pGraph;
 };