fix: try to scroll inline preview into view

src/autocomplete.js

@@ -90,6 +90,7 @@ class Autocomplete {
         }.bind(this));
 
         this.tooltipTimer = lang.delayedCall(this.updateDocTooltip.bind(this), 50);
+        this.popupTimer = lang.delayedCall(this.$updatePopupPosition.bind(this), 50);
 
         this.stickySelectionTimer = lang.delayedCall(function() {
             this.stickySelection = true;
@@ -143,6 +144,7 @@ class Autocomplete {
         }
         this.hideDocTooltip();
         this.stickySelectionTimer.cancel();
+        this.popupTimer.cancel();
         this.stickySelection = false;
     }
 
@@ -160,9 +162,14 @@ class Autocomplete {
                 this.tooltipTimer.call(null, null);
                 return;
             }
+
+            // Update the popup position after a short wait to account for potential scrolling
+            this.popupTimer.schedule();
+            this.tooltipTimer.schedule();
+        } else {
+            this.$updatePopupPosition();
+            this.tooltipTimer.call(null, null);
         }
-        this.$updatePopupPosition();
-        this.tooltipTimer.call(null, null);
     }
 
     $onPopupShow(hide) {

src/autocomplete/inline_test.js

@@ -42,6 +42,14 @@ var completions = [
         value: "f should not show inline",
         score: 0,
         hideInlinePreview: true
+    },
+    {
+        value: "long\nlong\nlong\nlong\nlong\nlong",
+        score: 0
+    },
+    {
+        value: "long\nlong\nlong\nlong\nlong\nlong".repeat(100),
+        score: 0
     }
 ];
 
@@ -261,6 +269,38 @@ module.exports = {
 
         done();
     },
+    "test: should scroll if inline preview outside": function(done) {
+        // Fill the editor with new lines to get the cursor to the bottom
+        // of the container
+        editor.execCommand("insertstring", "\n".repeat(200));
+
+        var deltaY;
+        var initialScrollBy = editor.renderer.scrollBy;
+        editor.renderer.scrollBy = function(varX, varY) {
+            deltaY = varY;
+        };
+
+        inline.show(editor, completions[6], "l");
+        editor.renderer.$loop._flush();
+
+        setTimeout(() => {
+            // Should scroll 5 lines to get the inline preview into view
+            assert.strictEqual(deltaY, 50);
+
+            inline.hide();
+            editor.renderer.$loop._flush();
+
+            inline.show(editor, completions[7], "l");
+            editor.renderer.$loop._flush();
+
+            setTimeout(() => {
+                // Should scroll as much as possbile while keeping the cursor on screen
+                assert.strictEqual(deltaY, 490);
+                editor.renderer.scrollBy = initialScrollBy;
+                done();
+            }, 50); 
+        }, 50);  
+    },
     tearDown: function() {
         inline.destroy();
         editor.destroy();

src/virtual_renderer.js

@@ -1620,6 +1620,24 @@ class VirtualRenderer {
                 className: "ace_ghost_text"
             };
             this.session.widgetManager.addLineWidget(this.$ghostTextWidget);
+
+            // Check wether the line widget fits in the part of the screen currently in view
+            var pixelPosition = this.$cursorLayer.getPixelPosition(insertPosition, true);
+            var el = this.container;
+            var height = el.clientHeight;
+            var fitsY = textLines.length * this.lineHeight < height - pixelPosition.top;
+
+            // If it fits, no action needed
+            if (fitsY) return;
+
+            // If it can fully fit in the screen, scroll down until it fits on the screen
+            // if it cannot fully fit, scroll so that the cursor is at the top of the screen
+            // to fit as much as possible.
+            if (textLines.length * this.lineHeight < height) {
+                this.scrollBy(0, (textLines.length - 1) * this.lineHeight);
+            } else {
+                this.scrollBy(0, pixelPosition.top);
+            }   
         }
 
     }