if the current input is blank, start completing with file system entries

avocadianmage · Sep 9, 2018 · f66d6da · f66d6da
1 parent 5ff2841
commit f66d6da
Showing 1 changed file with 31 additions and 4 deletions.
diff --git a/powershell/startup-scripts/key-handlers.ps1 b/powershell/startup-scripts/key-handlers.ps1
@@ -1,12 +1,12 @@
-# Ctrl+Home: bring cursor to start of input buffer.
+# Ctrl+Home: Bring cursor to start of input buffer.
 Set-PSReadLineKeyHandler -Key Ctrl+Home `
                          -BriefDescription BeginningOfInput `
                          -Description "Bring cursor to start of input" `
                          -ScriptBlock {
     [Microsoft.PowerShell.PSConsoleReadLine]::SetCursorPosition(0) 
 }
 
-# Ctrl+End: bring cursor to end of input buffer.
+# Ctrl+End: Bring cursor to end of input buffer.
 Set-PSReadLineKeyHandler -Key Ctrl+End `
                          -BriefDescription EndOfInput `
                          -Description "Bring cursor to end of input" `
@@ -17,13 +17,13 @@ Set-PSReadLineKeyHandler -Key Ctrl+End `
     [Microsoft.PowerShell.PSConsoleReadLine]::SetCursorPosition($text.Length) 
 }
 
-# Ctrl+Shift+Home: select text until start of input.
+# Ctrl+Shift+Home: Select text until start of input.
 Set-PSReadLineKeyHandler -Key Ctrl+Shift+Home `
                          -BriefDescription SelectBackwardToStart `
                          -Description "Select text until start of input" `
                          -ScriptBlock { selectLines $false }
 
-# Ctrl+Shift+End: select text to the end of the input buffer.
+# Ctrl+Shift+End: Select text to the end of the input buffer.
 Set-PSReadLineKeyHandler -Key Ctrl+Shift+End `
                          -BriefDescription SelectForwardToEnd `
                          -Description "Select text until end of input" `
@@ -48,3 +48,30 @@ function selectLines {
         $selectionLength = $newLength
     }
 }
+
+# Tab/Shift+Tab: Complete the input using the next completion. Use the first 
+# completion in the case of no input.
+Set-PSReadLineKeyHandler -Key Tab,Shift+Tab `
+                         -BriefDescription TabCompleteFirstOrNext `
+                         -Description "Complete the input using the next completion. Use the first completion in the case of no input" `
+                         -ScriptBlock {
+    param($key, $arg)
+
+    # If the current input is blank, use ".\" to start completing with file
+    # system entries.
+    $text = $null
+    [Microsoft.PowerShell.PSConsoleReadLine]::GetBufferState(
+        [ref]$text, [ref]$null)
+    if ([string]::IsNullOrWhitespace($text)) {
+        [Microsoft.PowerShell.PSConsoleReadLine]::RevertLine()
+        [Microsoft.PowerShell.PSConsoleReadLine]::Insert(".\")
+    }
+
+    # Call into the standard tab completion APIs. Cycle next/previous based on
+    # if shift is pressed.
+    if (($key.Modifiers -band [System.ConsoleModifiers]::Shift) -ne 0) {
+        [Microsoft.PowerShell.PSConsoleReadLine]::TabCompletePrevious()
+    } else {
+        [Microsoft.PowerShell.PSConsoleReadLine]::TabCompleteNext()
+    }
+}