You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

115 lines
3.5 KiB
Markdown

# Module CVAT-CANVAS
## Description
The CVAT module presents a canvas to viewing, drawing and editing of annotations.
- It has been written on typescript
- It contains the class ```Canvas``` and the enum ```Rotation```
## Commands
- Building of the module from sources in the ```dist``` directory:
```bash
npm run build
npm run build -- --mode=development # without a minification
```
- Running development server
```bash
npm run server
```
- Updating of a module version:
```bash
npm version patch # updated after minor fixes
npm version minor # updated after major changes which don't affect API compatibility with previous versions
npm version major # updated after major changes which affect API compatibility with previous versions
```
## Creation
Canvas is created by using constructor:
```js
const { Canvas } = require('./canvas');
const canvas = new Canvas();
```
- Canvas has transparent background
Canvas itself handles:
- Shape context menu (PKM)
- Image moving (mousedrag)
- Image resizing (mousewheel)
- Image fit (dblclick)
- Remove point (PKM)
- Polyshape editing (Shift + LKM)
## API
### Methods
All methods are sync.
```ts
html(): HTMLElement;
setup(frameData: FrameData, objectStates: ObjectState): void;
activate(clientID: number, attributeID?: number): void;
rotate(direction: Rotation): void;
focus(clientID: number, padding?: number): void;
fit(): void;
grid(stepX: number, stepY: number): void;
draw(enabled?: boolean, shapeType?: string, numberOfPoints?: number, initialState?: any): void | ObjectState;
split(enabled?: boolean): void | ObjectState;
group(enabled?: boolean): void | ObjectState;
merge(enabled?: boolean): void | ObjectState;
cancel(): any;
```
### CSS Classes/IDs
- Each drawn object (tag, shape, track) has id ```canvas_object_{objectState.id}```
- Drawn shapes and tracks have classes ```canvas_shape```,
```canvas_shape_activated```,
```canvas_shape_grouping```,
```canvas_shape_merging```,
```canvas_shape_drawing```
- Tags has a class ```canvas_tag```
- Canvas image has ID ```canvas_image```
### Events
Standard JS events are used.
```js
- canvas.setup
- canvas.activated => ObjectState
- canvas.deactivated
- canvas.moved => [ObjectState], x, y
- canvas.drawn => ObjectState
- canvas.edited => ObjectState
- canvas.splitted => ObjectState
- canvas.groupped => [ObjectState]
- canvas.merged => [ObjectState]
```
## States
![](images/states.svg)
## API Reaction
| | FREE | GROUPING | SPLITTING | DRAWING | MERGING | EDITING |
|------------|------|----------|-----------|---------|---------|---------|
| html() | + | + | + | + | + | + |
| setup() | + | + | + | + | + | - |
| activate() | + | - | - | - | - | - |
| rotate() | + | + | + | + | + | + |
| focus() | + | + | + | + | + | + |
| fit() | + | + | + | + | + | + |
| grid() | + | + | + | + | + | + |
| draw() | + | - | - | - | - | - |
| split() | + | - | + | - | - | - |
| group | + | + | - | - | - | - |
| merge() | + | - | - | - | + | - |
| cancel() | - | + | + | + | + | + |