Stamp tool

Pick an emoji or upload an image, then click or drag on the canvas to stamp it as image shapes.

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This example builds a stamp tool from a custom StateNode. A panel in the TopPanel slot lists the available stamps — clicking one activates the tool, and each click on the canvas places a stamp centered on the pointer. Holding the pointer down and dragging lays a trail of stamps spaced by the stamp size, and the whole drag undoes as a single step.

Every stamp is placed as an image shape backed by a shared asset created with editor.createAssets. Emoji stamps are drawn once to a PNG using a canvas element, which keeps them consistent in exports and across platforms; stamping the same stamp many times reuses a single asset.

The stamp options are plain data in an atom — to ship a new default stamp, add an entry to the array. The panel's upload button shows the runtime version: it reads an image file as a data URL, adds it as a new stamp option, and activates the tool with it.