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mods/sfinv_buttons/API.md

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+# API documentation for [`sfinv_buttons`]
+
+Use this very simple API to add your own buttons to the new tab. There is only
+one function: `sfinv_buttons.register_button`.
+
+## `sfinv_buttons.register_button(name, def)`
+
+* `name`: Unique button identifier
+* `def`: Configuration table (see below)
+
+### Fields of `def`
+* `title`: Human-readable text on the button
+* `action(player)`: Function is called when button is triggered
+    * `player`: The `ObjectRef` of the player who triggered the button
+    * Default behaviour: Nothing happens
+* `tooltip`: A tooltip for the button (optional, only use it for an additional,
+  non-critical explanation)
+* `image`: Texture name for the image to show left of the button (optional)
+* `show(player)`: Shall return `true` if the button should be displayed (optional)
+    * `player`: ObjectRef to player who triggered the button
+    * Default: Always shows button
+
+## Recommendations
+
+* Try to summarize the most important information on the button
+* Test if the button title still fits when having >= 9 and <= 18 buttons at a
+  resolution of 800×600
+* It is recommended to only add buttons to access core mod functionality and
+  not for every minor feature. The rule of thumb is to add at most 1 button per mod
+* If you like to add many buttons, consider adding your own `sfinv` page instead