FIX EXT-5517: clear hover face when cursor hovers over Nearby Media panel

Review #140
This isn't the most generalized solution, but it fixes the proximal
problem of selecting items in the Nearby Media panel, and is low risk
because the code change is isolated to that panel.

indra/newview/llpanelnearbymedia.cpp

@@ -231,6 +231,7 @@ void LLPanelNearByMedia::reshape(S32 width, S32 height, BOOL called_from_parent)
 const F32 AUTO_CLOSE_FADE_TIME_START= 4.0f;
 const F32 AUTO_CLOSE_FADE_TIME_END = 5.0f;
 
+/*virtual*/
 void LLPanelNearByMedia::draw()
 {
 	//LLUICtrl* new_top = gFocusMgr.getTopCtrl();
@@ -265,6 +266,21 @@ void LLPanelNearByMedia::draw()
 	}
 }
 
+/*virtual*/
+BOOL LLPanelNearByMedia::handleHover(S32 x, S32 y, MASK mask)
+{
+	LLPanel::handleHover(x, y, mask);
+	
+	// If we are hovering over this panel, make sure to clear any hovered media
+	// ID.  Note that the more general solution would be to clear this ID when
+	// the mouse leaves the in-scene view, but that proved to be problematic.
+	// See EXT-5517
+	LLViewerMediaFocus::getInstance()->clearHover();
+		
+	// Always handle
+	return true;
+}
+
 bool LLPanelNearByMedia::getParcelAudioAutoStart()
 {
 	return mParcelAudioAutoStart;

indra/newview/llpanelnearbymedia.h

@@ -56,6 +56,7 @@ public:
 	/*virtual*/ void handleVisibilityChange ( BOOL new_visibility );
 	/*virtual*/ void onTopLost ();
 	/*virtual*/ void reshape(S32 width, S32 height, BOOL called_from_parent);
+	/*virtual*/ BOOL handleHover(S32 x, S32 y, MASK mask);
 
 	// this is part of the nearby media *dialog* so we can track whether
 	// the user *implicitly* wants audio on or off via their *explicit*

indra/newview/skins/default/xui/en/panel_nearby_media.xml

@@ -2,6 +2,7 @@
 <panel
 	can_resize="true"
 	can_close="false"
+	mouse_opaque="true"
 	bg_opaque_image="Volume_Background" 
 	bg_alpha_image="Volume_Background" 
 	background_opaque="true"
@@ -132,6 +133,7 @@
 		  ame="OnOthers" />
 	</combo_box>
 	<scroll_list
+		name="media_list"
 		follows="left|top|bottom|right"
 		column_padding="0"
 		height="105"
@@ -140,8 +142,7 @@
 		bg_stripe_color="0.25 0.25 0.25 0.25"
 		top_pad="8"
 		left="10"
-		right="-10"
-		name="media_list">
+		right="-10">
 	  <scroll_list.columns
 		  type="checkbox"
 		  width="-1"
@@ -189,11 +190,9 @@
 		  left="10"
 		  right="-10"
 		  border_size="0"
-		  mouse_opaque="false"
 		  orientation="horizontal">
 		<layout_panel
 			name="stop"
-			mouse_opaque="false"
 			auto_resize="false"
 			user_resize="false"
 			layout="topleft"
@@ -221,7 +220,6 @@
 		</layout_panel>
 		<layout_panel
 			name="play"
-			mouse_opaque="false"
 			auto_resize="false"
 			user_resize="false"
 			layout="topleft"
@@ -249,7 +247,6 @@
 		</layout_panel>
 		<layout_panel
 			name="pause"
-			mouse_opaque="false"
 			auto_resize="false"
 			user_resize="false"
 			layout="topleft"
@@ -276,7 +273,6 @@
 		</layout_panel>
 		<layout_panel
 			name="volume_slider_ctrl"
-			mouse_opaque="false"
 			auto_resize="true"
 			user_resize="false"
 			follows="left|right"
@@ -301,7 +297,6 @@
 		</layout_panel>
 		<layout_panel
 			name="mute"
-			mouse_opaque="false"
 			auto_resize="false"
 			user_resize="false"
 			layout="topleft"
@@ -330,7 +325,6 @@
 		</layout_panel>
 		<layout_panel
 			name="zoom"
-			mouse_opaque="false"
 			auto_resize="false"
 			user_resize="false"
 			layout="topleft"
@@ -358,7 +352,6 @@
 		</layout_panel>
 		<layout_panel
 			name="unzoom"
-			mouse_opaque="false"
 			auto_resize="false"
 			user_resize="false"
 			layout="topleft"
@@ -387,7 +380,6 @@
 		<layout_panel
 			name="right_bookend"
 			width="0"
-			mouse_opaque="false"
 			user_resize="false" />
 	  </layout_stack>
 	</panel>