Advanced Window Snap is a script for AutoHotKey that expands upon Windows built-in window-snapping hotkeys.

README.md

Advanced Window Snap

Advanced Window Snap is a script for AutoHotKey that expands upon Windows built-in window-snapping hotkeys (which are Win + LEFT to snap an active window to the left half of a monitor and Win + RIGHT to snap a window to the right half of a monitor) by adding 9 additional snap methods.

Installation Steps

1. Install AutoHotKey
2. Copy or Download the AdvancedWindowSnap.ahk file to your computer and double click it to run it.
3. (Optional) To have the program run when you start up your computer, place the .ahk file into your computer's startup folder.
   • The Windows 7 Startup Folder can be accessed by mousing to Start > All Programs, then right-clicking on Startup and selecting "Open".
   • The Windows 8 Startup Folder can be accessed by tapping Win + R on your keyboard, then in the Open: field, type shell:startup then press Enter.

Advanced Window Snap Keybindings

Note: Keybindings are located at the bottom of the script. Please feel free to remove and/or modify them to suit your needs. You can use the following functions:

• SnapActiveWindowGrid(numRows, numCols, row, col)
• SnapActiveWindowGridSpan(numRows, numCols, row, col, rowSpan, colSpan)

Directional Arrow Hotkeys:

Hotkey	Behavior
Win + Alt + UP	Window will snap to the top half of the screen.
Win + Alt + DOWN	Window will snap to the bottom half of the screen.
Ctrl + Win + Alt + UP	Window will snap to the top third of the screen.
Ctrl + Win + Alt + DOWN	Window will snap to the bottom third of the screen.

Numberpad Hotkeys (Landscape):

These will work only if you have NumLock turned ON. These are ideal for Landscape/Ultrawide Monitors.

Hotkey	Behavior
Win + Alt + Numpad 4	Window will snap to the left fourth of the screen.
Win + Alt + Numpad 5	Window will snap to the center half of the screen.
Win + Alt + Numpad 6	Window will snap to the right fourth of the screen.

Numberpad Hotkeys (Portrait):

These will work only if you have NumLock turned ON. These are ideal for Portrait Monitors.

Hotkey	Behavior
Ctrl + Win + Numpad 8	Window will snap to the top third of the screen.
Ctrl + Win + Numpad 5	Window will snap to the middle third of the screen.
Ctrl + Win + Numpad 2	Window will snap to the bottom third of the screen

Numberpad Hotkeys (3x3 Grid):

These will work only if you have NumLock turned ON.

Hotkey	Behavior
Ctrl + Win + Alt + Numpad 7	Window will snap to the upper left third of the screen.
Ctrl + Win + Alt + Numpad 8	Window will snap to the upper center third of the screen.
Ctrl + Win + Alt + Numpad 9	Window will snap to the upper right third of the screen.
Ctrl + Win + Alt + Numpad 4	Window will snap to the center left third of the screen.
Ctrl + Win + Alt + Numpad 5	Window will snap to the center third of the screen.
Ctrl + Win + Alt + Numpad 6	Window will snap to the center right third of the screen.
Ctrl + Win + Alt + Numpad 1	Window will snap to the lower left third of the screen.
Ctrl + Win + Alt + Numpad 2	Window will snap to the lower center third of the screen.
Ctrl + Win + Alt + Numpad 3	Window will snap to the lower right third of the screen.

Changelog

• v1.2, 15 May 2019

  • Added SnapActiveWindowGridSpan to support rowSpan and colSpan

• v1.1, 15 May 2019

  • Added Grid

• v1.00, 08 Jan 2015

  • Initial Version

Recommendation For Editing AHK Files

If you plan on working with AutoHotKey files, consider using Sublime Text 3. Read my steps for setting up Sublime Text 3 to edit AutoHotKey files here: Working with AutoHotKey in Sublime Text.

AdvancedWindowSnap.ahk

/**
 * Advanced Window Snap
 * Snaps the active window to a position within a user-defined grid.
 *
 * @author Andrew Moore <andrew+github@awmoore.com>
 * @contributor jballi
 * @contributor park-brian
 * @contributor shinywong
 * @version 1.2
 */

/**
 * Resizes and moves the active window to a given position on a grid
 * @param {integer} numRows   The number of rows in the grid
 * @param {integer} numCols   The number of columns in the grid
 * @param {integer} row       The specific row within the grid to place the window
 * @param {integer} col       The specific column within the grid to place the window
 *
 * @example (Snap a window to the left third of the screen)
 * SnapActiveWindowGrid(1, 3, 1, 1);
 *
 * @example (Snap a window to the bottom half of the screen)
 * SnapActiveWindowGrid(2, 1, 2, 1);
 */
SnapActiveWindowGrid(numRows, numCols, row, col) {
    SnapActiveWindowGridSpan(numRows, numCols, row, col, 1, 1)
}

/**
 * Resizes and moves the active window to a given position on a grid, applying a rowSpan and colSpan
 * @param {integer} numRows   The number of rows in the grid
 * @param {integer} numCols   The number of columns in the grid
 * @param {integer} row       The specific row within the grid to place the window
 * @param {integer} col       The specific column within the grid to place the window
 * @param {integer} rowSpan   The specific row within the grid to place the window
 * @param {integer} colSpan   The specific column within the grid to place the window
 *
 * @example (Given a 4-column layout, snap a window to the rightmost column)
 * SnapActiveWindowGridSpan(1, 4, 1, 1, 1, 1);
 *
 * @example (Given a 4-column layout, snap a window to the centermost columns)
 * SnapActiveWindowGridSpan(1, 4, 1, 1, 1, 2);
 */
SnapActiveWindowGridSpan(numRows, numCols, row, col, rowSpan, colSpan) {

    WinGet activeWin, ID, A

    activeMon := GetMonitorIndexFromWindow(activeWin)

    SysGet, MonitorWorkArea, MonitorWorkArea, %activeMon%

    ; Determine the width and height of a grid cell
    height := (MonitorWorkAreaBottom - MonitorWorkAreaTop)/numRows
    width := (MonitorWorkAreaRight - MonitorWorkAreaLeft)/numCols

    ; Determine the x and y offsets
    posX  := MonitorWorkAreaLeft + (col - 1) * width
    posY  := MonitorWorkAreaTop + (row - 1) * height

    ; Apply rowSpan/colSpan after determining offsets
    width *= colSpan
    height *= rowSpan

    ; Use WinGetPosEx to determine position/size offsets (to remove gaps around windows)
    WinGetPosEx(activeWin, X, Y, realWidth, realHeight, offsetX, offsetY)

    ; Move and resize the active window
    WinMove, A,, (posX + offsetX), (posY + offsetY), (width + offsetX * -2), (height + (offsetY - 2) * -2)
}

/**
 * GetMonitorIndexFromWindow retrieves the HWND (unique ID) of a given window.
 * @param {Uint} windowHandle
 * @author shinywong
 * @link http://www.autohotkey.com/board/topic/69464-how-to-determine-a-window-is-in-which-monitor/?p=440355
 */
GetMonitorIndexFromWindow(windowHandle) {
    ; Starts with 1.
    monitorIndex := 1

    VarSetCapacity(monitorInfo, 40)
    NumPut(40, monitorInfo)

    if (monitorHandle := DllCall("MonitorFromWindow", "uint", windowHandle, "uint", 0x2))
        && DllCall("GetMonitorInfo", "uint", monitorHandle, "uint", &monitorInfo) {
        monitorLeft   := NumGet(monitorInfo,  4, "Int")
        monitorTop    := NumGet(monitorInfo,  8, "Int")
        monitorRight  := NumGet(monitorInfo, 12, "Int")
        monitorBottom := NumGet(monitorInfo, 16, "Int")
        workLeft      := NumGet(monitorInfo, 20, "Int")
        workTop       := NumGet(monitorInfo, 24, "Int")
        workRight     := NumGet(monitorInfo, 28, "Int")
        workBottom    := NumGet(monitorInfo, 32, "Int")
        isPrimary     := NumGet(monitorInfo, 36, "Int") & 1

        SysGet, monitorCount, MonitorCount

        Loop, %monitorCount% {
            SysGet, tempMon, Monitor, %A_Index%

            ; Compare location to determine the monitor index.
            if ((monitorLeft = tempMonLeft) and (monitorTop = tempMonTop)
                and (monitorRight = tempMonRight) and (monitorBottom = tempMonBottom)) {
                monitorIndex := A_Index
                break
            }
        }
    }

    return %monitorIndex%
}

;------------------------------
;
; Function: WinGetPosEx
;
; Description:
;
;   Gets the position, size, and offset of a window. See the *Remarks* section
;   for more information.
;
; Parameters:
;
;   hWindow - Handle to the window.
;
;   X, Y, Width, Height - Output variables. [Optional] If defined, these
;       variables contain the coordinates of the window relative to the
;       upper-left corner of the screen (X and Y), and the Width and Height of
;       the window.
;
;   Offset_X, Offset_Y - Output variables. [Optional] Offset, in pixels, of the
;       actual position of the window versus the position of the window as
;       reported by GetWindowRect.  If moving the window to specific
;       coordinates, add these offset values to the appropriate coordinate
;       (X and/or Y) to reflect the true size of the window.
;
; Returns:
;
;   If successful, the address of a RECTPlus structure is returned.  The first
;   16 bytes contains a RECT structure that contains the dimensions of the
;   bounding rectangle of the specified window.  The dimensions are given in
;   screen coordinates that are relative to the upper-left corner of the screen.
;   The next 8 bytes contain the X and Y offsets (4-byte integer for X and
;   4-byte integer for Y).
;
;   Also if successful (and if defined), the output variables (X, Y, Width,
;   Height, Offset_X, and Offset_Y) are updated.  See the *Parameters* section
;   for more more information.
;
;   If not successful, FALSE is returned.
;
; Requirement:
;
;   Windows 2000+
;
; Remarks, Observations, and Changes:
;
; * Starting with Windows Vista, Microsoft includes the Desktop Window Manager
;   (DWM) along with Aero-based themes that use DWM.  Aero themes provide new
;   features like a translucent glass design with subtle window animations.
;   Unfortunately, the DWM doesn't always conform to the OS rules for size and
;   positioning of windows.  If using an Aero theme, many of the windows are
;   actually larger than reported by Windows when using standard commands (Ex:
;   WinGetPos, GetWindowRect, etc.) and because of that, are not positioned
;   correctly when using standard commands (Ex: gui Show, WinMove, etc.).  This
;   function was created to 1) identify the true position and size of all
;   windows regardless of the window attributes, desktop theme, or version of
;   Windows and to 2) identify the appropriate offset that is needed to position
;   the window if the window is a different size than reported.
;
; * The true size, position, and offset of a window cannot be determined until
;   the window has been rendered.  See the example script for an example of how
;   to use this function to position a new window.
;
; * 20150906: The "dwmapi\DwmGetWindowAttribute" function can return odd errors
;   if DWM is not enabled.  One error I've discovered is a return code of
;   0x80070006 with a last error code of 6, i.e. ERROR_INVALID_HANDLE or "The
;   handle is invalid."  To keep the function operational during this types of
;   conditions, the function has been modified to assume that all unexpected
;   return codes mean that DWM is not available and continue to process without
;   it.  When DWM is a possibility (i.e. Vista+), a developer-friendly messsage
;   will be dumped to the debugger when these errors occur.
;
; Credit:
;
;   Idea and some code from *KaFu* (AutoIt forum)
;
; Author:
;
;    jballi
;
; Forum Link:
;
;    https://autohotkey.com/boards/viewtopic.php?t=3392
;-------------------------------------------------------------------------------
WinGetPosEx(hWindow,ByRef X="",ByRef Y="",ByRef Width="",ByRef Height="",ByRef Offset_X="",ByRef Offset_Y="") {
    Static Dummy5693
          ,RECTPlus
          ,S_OK:=0x0
          ,DWMWA_EXTENDED_FRAME_BOUNDS:=9

    ;-- Workaround for AutoHotkey Basic
    PtrType:=(A_PtrSize=8) ? "Ptr":"UInt"

    ;-- Get the window's dimensions
    ;   Note: Only the first 16 bytes of the RECTPlus structure are used by the
    ;   DwmGetWindowAttribute and GetWindowRect functions.
    VarSetCapacity(RECTPlus,24,0)
    DWMRC:=DllCall("dwmapi\DwmGetWindowAttribute"
        ,PtrType,hWindow                                ;-- hwnd
        ,"UInt",DWMWA_EXTENDED_FRAME_BOUNDS             ;-- dwAttribute
        ,PtrType,&RECTPlus                              ;-- pvAttribute
        ,"UInt",16)                                     ;-- cbAttribute

    if (DWMRC<>S_OK)
        {
        if ErrorLevel in -3,-4  ;-- Dll or function not found (older than Vista)
            {
            ;-- Do nothing else (for now)
            }
         else
            outputdebug,
               (ltrim join`s
                Function: %A_ThisFunc% -
                Unknown error calling "dwmapi\DwmGetWindowAttribute".
                RC=%DWMRC%,
                ErrorLevel=%ErrorLevel%,
                A_LastError=%A_LastError%.
                "GetWindowRect" used instead.
               )

        ;-- Collect the position and size from "GetWindowRect"
        DllCall("GetWindowRect",PtrType,hWindow,PtrType,&RECTPlus)
        }

    ;-- Populate the output variables
    X:=Left :=NumGet(RECTPlus,0,"Int")
    Y:=Top  :=NumGet(RECTPlus,4,"Int")
    Right   :=NumGet(RECTPlus,8,"Int")
    Bottom  :=NumGet(RECTPlus,12,"Int")
    Width   :=Right-Left
    Height  :=Bottom-Top
    OffSet_X:=0
    OffSet_Y:=0

    ;-- If DWM is not used (older than Vista or DWM not enabled), we're done
    if (DWMRC<>S_OK)
        Return &RECTPlus

    ;-- Collect dimensions via GetWindowRect
    VarSetCapacity(RECT,16,0)
    DllCall("GetWindowRect",PtrType,hWindow,PtrType,&RECT)
    GWR_Width :=NumGet(RECT,8,"Int")-NumGet(RECT,0,"Int")
        ;-- Right minus Left
    GWR_Height:=NumGet(RECT,12,"Int")-NumGet(RECT,4,"Int")
        ;-- Bottom minus Top

    ;-- Calculate offsets and update output variables
    NumPut(Offset_X:=(Width-GWR_Width)//2,RECTPlus,16,"Int")
    NumPut(Offset_Y:=(Height-GWR_Height)//2,RECTPlus,20,"Int")
    Return &RECTPlus
}

; Directional Arrow Hotkeys

; Snap to top half of screen (Win + Alt + Arrows)
; 2 rows, 1 column, first row, first column
#!Up::SnapActiveWindowGrid(2, 1, 1, 1)

; Snap to bottom half of screen
; 2 rows, 1 columns, second row, first column
#!Down::SnapActiveWindowGrid(2, 1, 2, 1)

; Snap to top third of screen (Ctrl + Win + Alt + Arrows)
; 3 rows, 1 column, first row, first column
^#!Up::SnapActiveWindowGrid(3, 1, 1, 1)

; Snap to bottom third of screen
; 3 rows, 1 column, third row, first column
^#!Down::SnapActiveWindowGrid(3, 1, 3, 1)


; Numberpad Hotkeys

; Snap to left fourth of screen (Win + Alt + Numpad)
; 1 row, 4 columns, first row, first column, rowspan 1, colspan 1
#!Numpad4::SnapActiveWindowGrid(1, 4, 1, 1)

; Snap to center half of screen
; 1 row, 4 columns, first row, second column, rowspan 1, colspan 2
#!Numpad5::SnapActiveWindowGridSpan(1, 4, 1, 2, 1, 2)

; Snap to right fourth of screen
; 1 row, 4 columns, first row, fourth column
#!Numpad6::SnapActiveWindowGrid(1, 4, 1, 4)


; Snap to upper third of screen (Win + Alt + Numpad)
; 3 rows, 1 column, first row, first column
^#Numpad8::SnapActiveWindowGrid(3, 1, 1, 1)

; Snap to middle third of screen
; 3 rows, 1 column, second row, first column
^#Numpad5::SnapActiveWindowGrid(3, 1, 2, 1)

; Snap to bottom third of screen
; 3 rows, 1 column, third row, first column
^#Numpad2::SnapActiveWindowGrid(3, 1, 3, 1)


; Snap to top left third of screen (Ctrl + Win + Alt + Numpad)
^#!Numpad7::SnapActiveWindowGrid(3, 3, 1, 1)

; Snap to top middle third of screen
^#!Numpad8::SnapActiveWindowGrid(3, 3, 1, 2)

; Snap to top right third of screen
^#!Numpad9::SnapActiveWindowGrid(3, 3, 1, 3)

; Snap to center left third of screen
^#!Numpad4::SnapActiveWindowGrid(3, 3, 2, 1)

; Snap to center third of screen
^#!Numpad5::SnapActiveWindowGrid(3, 3, 2, 2)

; Snap to center right third of screen
^#!Numpad6::SnapActiveWindowGrid(3, 3, 2, 3)

; Snap to bottom left third of screen
^#!Numpad1::SnapActiveWindowGrid(3, 3, 3, 1)

; Snap to bottom middle third of screen
^#!Numpad2::SnapActiveWindowGrid(3, 3, 3, 2)

; Snap to bottom  right third of screen
^#!Numpad3::SnapActiveWindowGrid(3, 3, 3, 3)

I asked this elsewhere, but I am trying to figure out how to snap to the left third of the screen.

@DanielGGordon

Hi Daniel,

Sorry it took so long for me to get back to you. I have updated the script so that you can now snap items along a grid that contains an arbitrary number of rows and columns. I've added the hotkeys for snapping to thirds in landscape mode:

Numberpad Hotkeys (Landscape):

These will work only if you have NumLock turned ON. These are ideal for Landscape Monitors.

Hotkey	Behavior
Win + Alt + Numpad 4	Window will snap to the left third of the screen.
Win + Alt + Numpad 5	Window will snap to the center third of the screen.
Win + Alt + Numpad 6	Window will snap to the right third of the screen.

I have also added some hotkeys to allow you to snap to one-ninths of a screen. These will probably only be useful for very large monitors.

Numberpad Hotkeys (3x3 Grid):

These will work only if you have NumLock turned ON.

Hotkey	Behavior
Ctrl + Win + Alt + Numpad 7	Window will snap to the upper left third of the screen.
Ctrl + Win + Alt + Numpad 8	Window will snap to the upper center third of the screen.
Ctrl + Win + Alt + Numpad 9	Window will snap to the upper right third of the screen.
Ctrl + Win + Alt + Numpad 4	Window will snap to the center left third of the screen.
Ctrl + Win + Alt + Numpad 5	Window will snap to the center third of the screen.
Ctrl + Win + Alt + Numpad 6	Window will snap to the center right third of the screen.
Ctrl + Win + Alt + Numpad 1	Window will snap to the lower left third of the screen.
Ctrl + Win + Alt + Numpad 2	Window will snap to the lower center third of the screen.
Ctrl + Win + Alt + Numpad 3	Window will snap to the lower right third of the screen.

Of course, you can write your own keybindings using the updated SnapActiveWindowGrid function. For example:

; Snap to center third of screen  (Win + Alt + Numpad)
; 1 row, 3 columns, first row, second column 
#!Numpad5::SnapActiveWindowGrid(1, 3, 1, 2)

Hey weird behavior I found while using this script. I ran Call of Duty: Modern Warfare in fullscreen mode and it would crash when I started it after a couple seconds. My screen would flicker and it would look like its trying to resize the game window and then it would crash. When I turn off the script, the game runs perfectly.

I wonder if there is extraneous window resizing going on here that we are not noticing.

Hey weird behavior I found while using this script. I ran Call of Duty: Modern Warfare in fullscreen mode and it would crash when I started it after a couple seconds. My screen would flicker and it would look like its trying to resize the game window and then it would crash. When I turn off the script, the game runs perfectly.

I wonder if there is extraneous window resizing going on here that we are not noticing.

Thanks ScarpMetal, in theory only the keybindings should call SnapActiveWindowGrid. I will see if I can replicate this, and check to see if the active window is fullscreen before doing anything.

Works great, and well commented, making it easy for me to tweak hotkeys and comment out stuff I don't need.

@DanielGGordon

Hi Daniel,

Sorry it took so long for me to get back to you. I have updated the script so that you can now snap items along a grid that contains an arbitrary number of rows and columns. I've added the hotkeys for snapping to thirds in landscape mode:
....

@park-brian

Tried it out, it works great. Also I think this used to have an issue with newer versions of windows and the windows not extending all the way to the corner, but now I see it does just fine.

One scenario that seems popular for widescreens - the middle 50% of the monitor. So for example, on a 3440 wide monitor, the first window would have the width of 860, the second windows would be 1720 wide, and the last 860 wide again. So a big window in the middle with two smaller ones on the side. I don't think that can be accomplished with this grid system.

Below is a screenshot of what I would want it to look like (it's not exact, I made these manually). I have seen a lot of people who use ultrawides who want this kind of a window setup.
25/50/25

EDIT: I was just thinking about this, you can just do SnapActiveWindowGrid(1, 4, 1, 2), and then all you need to do is keep the X/Y position, and double the width of the window. Gonna try that and then edit this comment once I figure that out.

EDIT: Ok so I basically made a copy of SnapActiveWindowGrid, and just changed the line that calls WinMove to multiply the width by 2. Now I can use this new function to snap to the middle 50% of the screen by doing SnapActiveWindowGridForDoubleWidth(1, 4, 1, 2). I can also snap to the left 2/3rds by doing SnapActiveWindowGridForDoubleWidth(1, 4, 1, 2).

Thanks for your comment Daniel! You can actually provide decimal values for the row/column arguments (so something like the following might work for you). Do you think a rowspan/colspan argument would be useful to add?

; Snap to left fourth of screen (Win + Alt + Numpad4)
; 1 row, 4 columns, first row, first column
#!Numpad4::SnapActiveWindowGrid(1, 4, 1, 1)

; Snap to center half of screen (Win + Alt + Numpad5)
; 1 row, 2 columns, first row, halfway between column 1 and column 2
#!Numpad5::SnapActiveWindowGrid(1, 2, 1, 1.5)

; Snap to right fourth of screen (Win + Alt + Numpad6)
; 1 row, 4 columns, first row, fourth column
#!Numpad6::SnapActiveWindowGrid(1, 4, 1, 4)

I went ahead and added a SnapActiveWindowGridSpan function which takes in rowSpan/colSpan arguments. You should now be able to do something like this:

; Snap to left fourth of screen (Win + Alt + Numpad)
; 1 row, 4 columns, first row, first column, rowspan 1, colspan 1
#!Numpad4::SnapActiveWindowGrid(1, 4, 1, 1)

; Snap to center half of screen
; 1 row, 4 columns, first row, second column, rowspan 1, colspan 2
#!Numpad5::SnapActiveWindowGridSpan(1, 4, 1, 2, 1, 2)

; Snap to right fourth of screen
; 1 row, 4 columns, first row, fourth column
#!Numpad6::SnapActiveWindowGrid(1, 4, 1, 4)

Hm I'm not sure. Might be overloading the function a bit. I'm not sure I'd want an extra param just for this use case. Didn't realize you can use decimals, I think that would be good enough. SnapActiveWindowGrid(1, 2, 1, 1.5) seems like exactly what I would want.

The other use case I was thinking is 2/3rd and 1/3rd. Left windows takes up 2/3rd of the screen, and the second window takes up the last 1/3rd. Looks like I can do this with SnapActiveWindowGrid(1, 1.5, 1, 1). Awesome!

@park-brian - I have noticed one thing, that the shortcuts do not work if the window is in a maximized state. I'll try a snap - and it doesn't work. Then I just resize the window to not be at the max - and the snapping works.

I just set offsetX and offsetY to 0, otherwise I get some seriously mis-sized windows. This leaves me with the same pixel-gap as the original script, of course. I'm not sure what the realWidth and realHeight variables represent, but maybe they should be used.

If you can better document the WinGetPosEx function (e.g. with links to the documentation no all the DllCalls and explanation of exactly what values are being stored in pointers on each line of code) then I can do my best to debug this. As of now, it's pretty mysterious to me.

I am still using this script (without the offsets) rather than the original because the interface is designed nicely. Thanks for this work. I really would love it if a 100% functional version of this script emerged. Window snap is a big part of my workflow and these little gaps are annoying.

Has anyone got a Windows 10 version to share? :) It seems to not be working on Windows 10 with AHK V1.

@park-brian hello, I couldn't figure how to adjust position width/height of specific apps. Discord or VSCode for example have too big height, resizing window few pixels too long at the bottom, cutting a visibiltiy from bottom, which can be quite annoying for apps like VSC for example. Rest of the apps have the opossite problem - they're resized too long from the top - exact same amoutn pf pixels afaik. Would really appreciate your help.