---
name: Vergrootglas bij selectie
overview: Add a magnifier (circular zoom with crosshair and X/Y coordinates near the cursor) to the snip overlay and the screencast region selector, with a settings checkbox that is on by default. Release as 1.1.5.
todos:
  - id: setting
    content: ShowMagnifier (default true) toevoegen aan AppSettings
    status: completed
  - id: control
    content: "MagnifierControl maken: ronde zoom, raster, kruisdraad, X/Y-badge, plaatsing bij cursor met randcorrectie"
    status: completed
  - id: snip
    content: Vergrootglas in RegionCaptureWindow + doorgeven vanuit App.BeginSnip
    status: completed
  - id: screencast
    content: Vergrootglas in RegionSelectorWindow met vooraf vastgelegd beeld vanuit RecordingController.BeginSelection
    status: completed
  - id: settings-ui
    content: Checkbox in SettingsWindow (tab Sneltoetsen) laden en opslaan
    status: completed
  - id: release
    content: CHANGELOG 1.1.5, README, versienummers, build.ps1 draaien, commit/tag 1.1.5 en pushen
    status: completed
isProject: false
---

# Vergrootglas bij het kiezen van een gebied (1.1.5)

## Starting point
- kniip has no magnifier yet. The snip overlay [src/Kniip/Capture/RegionCaptureWindow.xaml](src/Kniip/Capture/RegionCaptureWindow.xaml) shows a frozen screenshot (`Frozen`), a dim layer, the selection and a `W × H` badge.
- The screencast selector [src/Kniip/Recording/RegionSelectorWindow.xaml](src/Kniip/Recording/RegionSelectorWindow.xaml) is a transparent overlay over the live screen. It has no image to zoom into.

## Approach

```mermaid
flowchart LR
    Settings["AppSettings.ShowMagnifier"] --> App["App.BeginSnip"]
    Settings --> Rec["RecordingController.BeginSelection"]
    App -->|"frozen image + flag"| Snip[RegionCaptureWindow]
    Rec -->|"capture per screen + flag"| Sel[RegionSelectorWindow]
    Snip --> Mag[MagnifierControl]
    Sel --> Mag
```

1. **Setting**: in [src/Kniip/Settings/AppSettings.cs](src/Kniip/Settings/AppSettings.cs) add
   `public bool ShowMagnifier { get; set; } = true;` with a Dutch doc comment.
2. **Shared control**: new `src/Kniip/Capture/MagnifierControl.xaml(.cs)` (UserControl, `IsHitTestVisible="False"`), styled like the screenshot:
   - A round clipped area (about 130 DIP) showing an `Image` of the frozen bitmap with `NearestNeighbor` scaling. A `CroppedBitmap` of about 15x15 physical pixels around the cursor is enlarged around 8x.
   - A pixel grid, a blue crosshair through the center pixel and a small square on the center pixel. The crosshair uses `AccentBrush`, the ring is white with a shadow.
   - Below the circle, a badge in the same style as `SizeBadge` with `X: … Y: …` in physical screen coordinates.
   - Method `Update(BitmapSource frozen, System.Drawing.Point physicalRelative, System.Drawing.Point screenPoint)`. Pixels outside the image are left black.
   - Placement: bottom-right of the cursor at about 20 DIP offset. It flips left and/or up near the screen edge.
3. **Snip overlay** [src/Kniip/Capture/RegionCaptureWindow.xaml.cs](src/Kniip/Capture/RegionCaptureWindow.xaml.cs):
   - Add a constructor parameter `bool showMagnifier` and add `<local:MagnifierControl x:Name="Magnifier" Visibility="Collapsed"/>` to the Grid.
   - In `OnMouseMove`, update and show the magnifier while it is on (before and during dragging). Not in window-pick mode (`PicksWindow`), because exact pixels don't matter there. Hide it on `MouseLeave`.
   - [src/Kniip/App.xaml.cs](src/Kniip/App.xaml.cs) `BeginSnip` passes `Settings.ShowMagnifier`.
4. **Screencast selector** [src/Kniip/Recording/RegionSelectorWindow.xaml.cs](src/Kniip/Recording/RegionSelectorWindow.xaml.cs):
   - Add an optional `BitmapSource? frozen` constructor parameter. When it is set, the same magnifier runs in `OnMouseMove` (also while hovering over windows, because you can drag from there).
   - [src/Kniip/Recording/RecordingController.cs](src/Kniip/Recording/RecordingController.cs) `BeginSelection`: if `_settings.ShowMagnifier` is on, call `ScreenGrabber.Capture(screen.Bounds)` per screen *before* the selectors are shown, so the overlay is not in the image. Otherwise pass `null`.
5. **Settings screen** [src/Kniip/Settings/SettingsWindow.xaml](src/Kniip/Settings/SettingsWindow.xaml) tab **Sneltoetsen**: below the hotkeys, add a card title "Gebied kiezen" with
   `<CheckBox x:Name="MagnifierBox" Content="Vergrootglas tonen bij het kiezen van een gebied (knipsel en screencast)" />`.
   In [SettingsWindow.xaml.cs](src/Kniip/Settings/SettingsWindow.xaml.cs), add a line to `LoadFrom` (around line 100) and to the save step (around line 444).
6. **Release 1.1.5**:
   - [CHANGELOG.md](CHANGELOG.md) gets a new section `## 1.1.5 - 2026-11-09` with a **Nieuw** entry for the magnifier (round zoom with crosshair and X/Y, for both snips and screencasts) and how to turn it off.
   - [README.md](README.md): the version table and build comment go to 1.1.5.
   - Version 1.1.4 becomes 1.1.5 in [build.ps1](build.ps1), [installer/Kniip.iss](installer/Kniip.iss) and [src/Kniip/Kniip.csproj](src/Kniip/Kniip.csproj).
   - Run `.\build.ps1`, then commit "1.1.5", tag `1.1.5` and push, the same way as 1.1.4. You create the release on git.hibbit.net yourself; I'll supply the changelog text.