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| author | Colin Okay <colin@cicadas.surf> | 2022-07-08 15:09:33 -0500 |
|---|---|---|
| committer | Colin Okay <colin@cicadas.surf> | 2022-07-08 15:09:33 -0500 |
| commit | 7d65547961ed7ac007f8c873d179f9db97d64fa2 (patch) | |
| tree | eb7151d6ef5d6cba4b673dda06cb2eb0d30197d1 /README.org | |
| parent | 66c7d24dc58e8fe025e6050c0051349b3923e67c (diff) | |
[doc] readme, copy
Diffstat (limited to 'README.org')
| -rw-r--r-- | README.org | 6 |
1 files changed, 3 insertions, 3 deletions
@@ -99,11 +99,11 @@ The shutdown method is optional and is called right before the application exits *** The Display Tree Protocol: Units and Containers -Objects that render to the screen are organized into a display tree. There are two basic kinds of objects: units and containers. Units are, roughly, "what you want to display" and containers are "when and where you want to display it". Additionally, containers hold a list of units. +Objects that render to the screen are organized into a display tree. There are two basic kinds of objects: **units** and **containers**. Units are what you want to display and containers are for controlling when and where you want to display those units. -In general, the last thing added to a container will be the last thing rendered - i.e. it will be "on top". Containers are themselves units, so they too can be added to other containers. Nesting of containers allows you to render a one set of units before or after some other set of units. +Units are added to and removed from containers, and a unit will belong to at most one container at a time. In general, the last thing added to a container will be the last thing rendered - i.e. it will appear to be "on top". Containers are themselves units, so they too can be added to other containers. Nesting of containers allows you to render a one set of units before or after some other set of units. -The application is a container, and is the only unit that does not need to be added to a scene. Nothing else will display until it becomes part of the display tree rooted at the application. +The application is itself a container, and is the only unit that does not need to be added to a scene. Nothing no unit will display until it becomes part of the display tree rooted at the application. Containers have "bounds", which are screen coordinates for the left, right, top, and bottom of the region inside of which units will be displayed. If a unit moves out of bounds, it will not show up on the screen, and will not receive mouse events. (It may, however, still be focused - and hence receive key events.) The bounds of the application are the visible window itself. Other containers may have custom bounds. |