document slip-drag of region contents

include/region-slip-drag.html

@@ -0,0 +1,18 @@
+<p>
+It's possible to move the contents of regions in time, without moving the
+regions' start or end points. This is sometimes known as "slip editing".
+</p>
+<p>
+To do this, hold the
+<kbd class="mod1"></kbd> and <kbd class="mod3"></kbd> keys
+while dragging the region or regions. As you click, the cursor will
+change to a double-headed arrow, and when you start dragging, the time from the
+start of the underlying content to the start of the clicked region is displayed.
+</p>
+<p>
+<img src="/images/slip-drag.png" alt="region slip-drag"><br>
+As you drag, the region start and end points will remain
+fixed, but the audio or MIDI content of the region will move,
+as long as the underlying source extends beyond the region bounds.
+</p>
+

master-doc.txt

@@ -1244,6 +1244,13 @@ uri: editing-and-arranging/change-region-lengths/pushpull-trimming
 part: subchapter
 ---
 
+---
+title: Move Region Contents
+include: region-slip-drag.html
+link: region-slip-drag
+part: subchapter
+---
+
 ---
 title: Stretching
 include: stretching-regions.html