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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">Dear colleagues:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">I wanted to gauge your opinion on a slightly different approach that addresses both John’s stateless behaviors use case as well as make it unnecessary to change existing event
handling APIs but still enforce the right order of event handler execution.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">Let’s call it a Split Input Map (more details later).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">Control gets an InputMap property which stores the
<b><u>user</u></b> event handlers and the user key bindings.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">Skin has a SkinInputMap, a similar construct, which stores the event handlers and the key bindings registered by the behavior. The SkinInputMap comes in two flavors: one for
the stateless behavior use case, and one for stateful behavior use case. In either case the skin input map is set via Skin.setSkinInputMap() (a placeholder name, can be changed).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">The difference between the two is the signature of the “function” mapped to a FunctionTag: the stateless requires Consumer<C extends Control>, and a stateful accepts a simple
Runnable.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">Furthermore, the event handling priority can be encapsulated within the input maps. For example, any event handler registered via either InputMap or SkinInputMap is guaranteed
to be called according to its priority. For example, we could have five levels (listed in the order of precedence):<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">USER_HIGH<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""> SKIN_HIGH<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">USER_MID<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""> SKIN_LOW<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">USER_LOW<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">Basically, event handlers added to the control’s InputMap can have { USER_HIGH, USER_MID, USER_LOW } priority, and those added to SkinInputMap can have { SKIN_HIGH, SKIN_LOW
}. This makes it unnecessary to change the existing event handling APIs but solves the issue with undetermined order of event handlers execution that we currently have in Controls.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">Comment:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">SkinInputMap is basically an equivalent of BehaviorContext in John’s proposal, and priority levels are unambiguous extension of Michael’s EventHandlerPriority.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">What do you think?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Iosevka Fixed SS16"">-andy<o:p></o:p></span></p>
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