Terminal-style command history in the Cocoa debugger

Cocoa/Document.xib

@@ -112,7 +112,7 @@
                     <textField focusRingType="none" verticalHuggingPriority="750" mirrorLayoutDirectionWhenInternationalizing="never" allowsCharacterPickerTouchBarItem="NO" id="l22-S8-uji">
                         <rect key="frame" x="0.0" y="0.0" width="921" height="24"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" flexibleMaxY="YES"/>
-                        <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" selectable="YES" editable="YES" state="on" focusRingType="none" id="p3j-nS-44f">
+                        <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" selectable="YES" editable="YES" state="on" focusRingType="none" id="p3j-nS-44f" customClass="GBTerminalTextFieldCell">
                             <font key="font" metaFont="fixedUser" size="11"/>
                             <color key="textColor" red="1" green="1" blue="1" alpha="1" colorSpace="calibratedRGB"/>
                             <color key="backgroundColor" red="0.16470588235294117" green="0.16470588235294117" blue="0.16470588235294117" alpha="1" colorSpace="calibratedRGB"/>

Cocoa/GBTerminalTextFieldCell.h

@@ -0,0 +1,5 @@
+#import <Cocoa/Cocoa.h>
+
+@interface GBTerminalTextFieldCell : NSTextFieldCell
+
+@end

Cocoa/GBTerminalTextFieldCell.m

@@ -0,0 +1,73 @@
+#import <Carbon/Carbon.h>
+#import "GBTerminalTextFieldCell.h"
+
+@interface GBTerminalTextView : NSTextView
+@end
+
+@implementation GBTerminalTextFieldCell
+{
+    GBTerminalTextView *field_editor;
+}
+
+- (NSTextView *)fieldEditorForView:(NSView *)controlView
+{
+    if (field_editor) {
+        return field_editor;
+    }
+    field_editor = [[GBTerminalTextView alloc] init];
+    [field_editor setFieldEditor:YES];
+    return field_editor;
+}
+
+@end
+
+@implementation GBTerminalTextView
+{
+    NSMutableOrderedSet *lines;
+    NSUInteger current_line;
+}
+
+- (instancetype)init
+{
+    self = [super init];
+    if (!self) {
+        return NULL;
+    }
+    lines = [[NSMutableOrderedSet alloc] init];
+    return self;
+}
+
+- (void)moveUp:(id)sender
+{
+    if (current_line != 0) {
+        current_line--;
+        [self setString:[lines objectAtIndex:current_line]];
+    }
+}
+
+- (void)moveDown:(id)sender
+{
+    if (current_line == [lines count]) {
+        return;
+    }
+    current_line++;
+    if (current_line == [lines count]) {
+        [self setString:@""];
+    }
+    else {
+        [self setString:[lines objectAtIndex:current_line]];
+    }
+}
+
+-(void) insertNewline:(id)sender
+{
+    if ([self.string length]) {
+        NSString *string = [self.string copy];
+        [lines removeObject:string];
+        [lines addObject:string];
+    }
+    [super insertNewline:sender];
+    current_line = [lines count];
+}
+
+@end