add action to reset UI layout, resize_headlines parameter checking

tt-rss.js

@@ -376,8 +376,10 @@ function resize_headlines(delta_x, delta_y) {
 	if (getInitParam("theme") == "3pane") {
 
 		if (c_frame.offsetLeft > feeds_frame.offsetWidth + feeds_frame.offsetLeft + 100) {
+			if (delta_x != undefined) {
 				hor_offset = delta_x;
 			}
+		}
 
 		debug("resize_headlines: HOR-mode");
 
@@ -391,7 +393,9 @@ function resize_headlines(delta_x, delta_y) {
 
 	} else {
 
+		if (delta_y != undefined) {
 			ver_offset = delta_y;
+		}
 
 		debug("resize_headlines: VER-mode");
 
@@ -578,6 +582,12 @@ function quickMenuGo(opid) {
 			Effect.Appear("hotkey_help_overlay", {duration : 0.3});
 		}
 
+		if (opid == "qmcResetUI") {
+			hor_offset = 0;
+			ver_offset = 0;
+			resize_headlines();
+		}
+
 	} catch (e) {
 		exception_error("quickMenuGo", e);
 	}

tt-rss.php

@@ -165,6 +165,8 @@ window.onload = init;
 					<option disabled>--------</option>
 					<option style="color : #5050aa" disabled><?php echo __('Other actions:') ?></option>				
 					<option value="qmcAddFilter"><?php echo __('&nbsp;&nbsp;Create filter') ?></option>
+					<option value="qmcResetUI"><?php echo __('&nbsp;&nbsp;Reset UI layout') ?></option>
+
 					<option value="qmcHKhelp"><?php echo __('&nbsp;&nbsp;Keyboard shortcuts') ?></option>
 			</select>
 		</div>