Paint a brush stroke along a straight line

`↑ Shift` + `Mouse left click`

All hotkeys for Affinity Photo

Editing Resize Document	`Alt` + `Ctrl` + `I`
Editing Resize Canvas	`Alt` + `Ctrl` + `C`
Painting Paint a brush stroke along a straight line	`↑ Shift` + `Mouse left click`
Editing Select overlapping layer content	`Alt` + `Mouse left click`
Editing Reset Selection Box	`.`
Editing Toggle Snapping	`;`
Vector-specific Edit curves as you draw	`Ctrl`
Editing Switch between Stroke/Fill (or Color 1/Color 2) color selectors (Color and Swatches panels)	`X`
Editing Swap Stroke/Fill (or Color 1/Color 2) color selectors	`↑ Shift` + `X`
Editing Set No fill on Stroke/Fill (or Color 1/Color 2) color selectors	`/`
Tools Dodge, Burn and Sponge Brush Tool cycle	`O`
Editing Flip golden spiral overlay (Crop Tool enabled)	`↑ Shift` + `O`
Editing (drag attribute text label) Modify attribute listed on a panel or dialog	`Mouse movement`
Vector-specific (drag control handle) Snap a curve's control handle to 45° intervals	`↑ Shift` + `Mouse movement`
Action (Transforming) (drag corner handle then hold down right mouse button) Rotate around opposite corner	`Mouse movement` then `Mouse right click`
Action (Transforming) Cancel a sizing, moving, or creating operation	`Esc`
Action (Transforming) Mirror shearing	`Ctrl` + `Mouse movement`
Pixel selection/Mask Move selection in 1-pixel increments	`← ↑ → ↓`
Pixel selection/Mask Move selection in 10-pixel increments	`↑ Shift` + `← ↑ → ↓`
Painting Picks up a new brush color	`Alt` + `Mouse movement`
Vector-specific Convert to Curves	`Ctrl` + `⤶ Enter`
File New Document	`Ctrl` + `N`
File New From Clipboard	`Ctrl` + `Alt` + `↑ Shift` + `N`
File Open Document	`Ctrl` + `O`
File Close Document/Close App (when no documents open)	`Ctrl` + `W`
File Switch Document/View	`Ctrl` + `⭾ Tab`
File Save	`Ctrl` + `S`
File Save As	`Ctrl` + `↑ Shift` + `S`
File Export	`Ctrl` + `Alt` + `↑ Shift` + `S`
File Print	`Ctrl` + `P`
Tools: Develop Persona only Overlay Gradient Tool	`G`
View View Tool	`H`
Tools Move Tool	`V`
Tools Color Picker Tool	`I`
Tools: Develop Persona only Crop Tool	`C`
Tools: Develop Persona only White Balance Tool	`W`
Tools: Liquify Persona only Liquify Push Forward Tool	`P`
Tools: Develop Persona only Zoom Tool	`Z`
Tools: Export Persona only Slice Tool	`S`
Tools: Panorama Persona only Erase From Source Image Mask Tool	`U`
Tools: Liquify Persona only Liquify Twirl Tool	`T`
Tools Retouch Tools cycle	`J`
Tools: Develop Persona only Overlay Paint Tool	`B`
Tools: Develop Persona only Overlay Erase Tool	`E`
Tools Marquee Selection Tools cycle	`M`
Tools: Panorama Persona only Add To Source Image Mask Tool	`L`
Tools: Develop Persona only Red Eye Removal Tool	`R`
Layer operations Toggle between Frequency Separation layers	`F`
Tools: Panorama Persona only Transform Source Image Tool	`A`
Edit Undo	`Ctrl` + `Z`
Edit Redo	`Ctrl` + `Y`
Edit Copy Merged	`Ctrl` + `↑ Shift` + `C`
Edit Paste Style	`Ctrl` + `↑ Shift` + `V`
Edit Paste FX	`↑ Shift` + `Alt` + `V`
Edit Paste Inside	`Ctrl` + `Alt` + `V`
Edit Paste without Format	`Ctrl` + `Alt` + `↑ Shift` + `V`
Edit Fill	`↑ Shift` + `F5`
Edit Inpaint	`Alt` + `Del`
Layer operations Select All Layers	`Alt` + `Ctrl` + `A`
Layer operations Group	`Ctrl` + `G`
Layer operations Ungroup	`Ctrl` + `↑ Shift` + `G`
Layer operations Duplicate	`Ctrl` + `J`
Liquify Persona Invert Mask	`Ctrl` + `I`
Layer operations Move to Front	`Ctrl` + `↑ Shift` + `]`
Layer operations Move Forward One	`Ctrl` + `]`
Layer operations Move to Back	`Ctrl` + `↑ Shift` + `[`
Layer operations Move Back One	`Ctrl` + `[`
Layer operations Show All	`Ctrl` + `Alt` + `↑ Shift` + `H`
Layer operations Unlock All	`Ctrl` + `Alt` + `↑ Shift` + `L`
Layer operations New Layer	`Ctrl` + `↑ Shift` + `N`
Layer operations Merge Down	`Ctrl` + `E`
Layer operations Merge Selected	`Ctrl` + `↑ Shift` + `E`
Layer operations Merge Visible	`Ctrl` + `Alt` + `↑ Shift` + `E`
Layer: Live Projection only Edit Live Projection	`Ctrl` + `\` + `P`
Painting Change selected layer content/brush tool's opacity	`Num 0` - `Num 9`
Painting Increase/decrease brush width	`]`
Painting Increase/decrease brush width	`[`
Painting (drag up / down) Decrease/increase brush hardness with on-screen readout	`Mouse movement`
Text shortcuts Bigger text	`Ctrl` + `+`
Text shortcuts Smaller text	`Ctrl` + `<`
Text shortcuts Precise bigger text	`Ctrl` + `Alt` + `+`
Text shortcuts Precise smaller text	`Ctrl` + `Alt` + `<`
Text shortcuts Tighten	`Alt` + `←`
Text shortcuts Loosen	`Alt` + `→`
Text shortcuts Tighten More	`Ctrl` + `Alt` + `←`
Text shortcuts Loosen More	`Ctrl` + `Alt` + `→`
Pixel selection/Mask Grow/Shrink	`Ctrl` + `B`
Adjustment and Filter shortcuts HSL (Adjustment)	`Ctrl` + `U`
Text shortcuts Show Character	`Ctrl` + `T`
Text shortcuts Show Typography	`Ctrl` + `↑ Shift` + `T`
Text shortcuts Superscript	`Ctrl` + `↑ Shift` + `=`
Text shortcuts Subscript	`Ctrl` + `Alt` + `-`
Text shortcuts Align Left	`Ctrl` + `Alt` + `L`
Text shortcuts Align Center	`Ctrl` + `Alt` + `C`
Pixel selection/Mask Refine Edges	`Ctrl` + `Alt` + `R`
Text shortcuts Justify Left	`Ctrl` + `Alt` + `\|`
Text shortcuts Increase Paragraph Leading	`Alt` + `↓`
Text shortcuts Decrease Paragraph Leading	`Alt` + `↑`
Text shortcuts Precise Increase Paragraph Leading	`Ctrl` + `Alt` + `↓`
Text shortcuts Precise Decrease Paragraph Leading	`Ctrl` + `Alt` + `↑`
Text shortcuts Raise Baseline	`Alt` + `↑ Shift` + `↑`
Text shortcuts Lower Baseline	`Alt` + `↑ Shift` + `↓`
Text shortcuts Precise Raise Baseline	`Ctrl` + `Alt` + `↑ Shift` + `↑`
Text shortcuts Precise Lower Baseline	`Ctrl` + `Alt` + `↑ Shift` + `↓`
Text shortcuts Spelling Options	`Ctrl` + `↑ Shift` + `;`
Text shortcuts Line Break	`↑ Shift` + `⤶ Enter`
Text shortcuts Non Breaking Space	`Alt` + `Space`
Text shortcuts En Dash	`Alt` + `-`
Text shortcuts Em Dash	`Alt` + `↑ Shift` + `-`
View Zoom In	`Ctrl` + `=`
View Zoom Out	`Ctrl` + `-`
View Zoom to Fit	`Ctrl` + `0`
View (double click on Zoom Tool icon) Zoom to Fit	`Mouse double click`
View (double click on Zoom Tool icon) (Zoom to) 100%	`Ctrl` + `1`
View (Zoom to) 200%	`Ctrl` + `2`
View (Zoom to) 400%	`Ctrl` + `3`
View (Zoom to) 800%	`Ctrl` + `4`
View (Zoom to) Actual Size	`Ctrl` + `8`
View (Zoom to) Pixel Size	`Ctrl` + `9`
View Hot key zoom in	`Space` + `Ctrl` + `Mouse left click`
View Hot key zoom out	`Space` + `Alt` + `Mouse left click`
View Hot key panning	`Space`
View Scroll vertically up/down	`Mouse wheel up and down`
View Scroll horizontally left/right	`↑ Shift` + `Mouse wheel up and down`
View Switch between views	`Ctrl` + `
View Show Rulers	`Ctrl` + `R`
View Show Guides	`Ctrl` + `;`
View Show Grid	`Ctrl` + `'`
View Grid Plane cycle	`'`
View Split View cycle (not Photo Persona)	`,`
Liquify Persona Mask All	`Ctrl` + `A`
Liquify Persona Clear Mask	`Ctrl` + `D`
Pixel selection/Mask Invert Pixel Selection	`Ctrl` + `↑ Shift` + `I`
Pixel selection/Mask (drag down) Add to selection (Marquee/Free hand selection tools only)	`Mouse movement`
Pixel selection/Mask Remove from selection	`Alt`
Pixel selection/Mask Feather	`↑ Shift` + `F6`
Pixel selection/Mask (click layer thumbnail) Selection from layer	`Ctrl` + `Mouse left click`
Pixel selection/Mask Selection from layer	`Ctrl` + `↑ Shift` + `O`
Pixel selection/Mask (click on page) Polygon selection (Freehand Selection Tool only)	`Ctrl` + `↑ Shift` + `Mouse left click`
Pixel selection/Mask Quick Mask	`Q`
Workspace Show/Hide Studio (panels)	`Ctrl` + `↑ Shift` + `H`
Workspace Show/Hide Toolbar	`Ctrl` + `Alt` + `T`
Workspace Toggle UI	`⭾ Tab`
Workspace Hide Workspace	`Ctrl` + `H`
Adjustment and Filter shortcuts Levels (Adjustment)	`Ctrl` + `L`
Adjustment and Filter shortcuts Curves (Adjustment)	`Ctrl` + `M`
Adjustment and Filter shortcuts Black and White (Adjustment)	`Ctrl` + `Alt` + `↑ Shift` + `B`
Adjustment and Filter shortcuts Repeat Filter	`Ctrl` + `F`
Misc. Preferences	`Ctrl` + `,`