API addition to Region & change to SkinBase method signatures

[Jonathan Giles]

+1

-- Jonathan

On 17/04/2013 10:32 a.m., Jasper Potts wrote:
> Hi All,
>
> We have been endlessly chasing bugs in UI Controls Skins where we are 
> not reliably and consistently snapping to pixels the insets/padding 
> values used in computePref/Min/Max etc methods and in the 
> layoutChildren method.
>
> So I am suggesting adding some helper methods to Region and passing in 
> values to the compute methods so that its much easier for developers 
> to have the correctly snapped values at hand.
>
> *Region Additions*
>
> *public class Region {*
> *    …..*
> *    public int snappedTopInset()*
> *    public int snappedBottomInset()*
> *    public int snappedRightInset()*
> *    public int snappedBottomInset()*
> *    …..*
> *}*
>
> These will the the equivalent of *"snapSize(getInsets().getTop())" 
> *but implemented in a more efficient way.
>
> *Changes to SkinBase*
> *OLD*
> *public abstract class SkinBase<C extends Control> implements Skin<C> {*
> *    …..*
> *    protected double computeMinWidth(double height) *
> *    protected double computeMinHeight(double width) *
> *    protected double computeMaxWidth(double height)*
> *    protected double computeMaxHeight(double width)*
> *    protected double computePrefWidth(double height)*
> *    protected double computePrefHeight(double width)*
> *    public double getBaselineOffset()*
> *    …..*
> *} *
>
> *NEW*
> *public abstract class SkinBase<C extends Control> implements Skin<C> {*
> *    …..*
> *    protected double computeMinWidth(double height, int topInset, int 
> rightInset, int bottomInset, int leftInset) *
> *    protected double computeMinHeight(double width, int topInset, int 
> rightInset, int bottomInset, int leftInset) *
> *    protected double computeMaxWidth(double height, int topInset, int 
> rightInset, int bottomInset, int leftInset)*
> *    protected double computeMaxHeight(double width, int topInset, int 
> rightInset, int bottomInset, int leftInset)*
> *    protected double computePrefWidth(double height, int topInset, 
> int rightInset, int bottomInset, int leftInset)*
> *    protected double computePrefHeight(double width, int topInset, 
> int rightInset, int bottomInset, int leftInset)*
> *    public double computeBaselineOffset()*
> *    …..*
> *}*
>
> The *topInsets* etc will be calculated as 
> *getSkinnable().snappedTopInset()*. The change from 
> *getBaselineOffset()* to *computeBaselineOffset()* is just to make it 
> clear this method is responsible for computing this value not getting 
> one someone else has computed. We are not passing insets into 
> *computeBaselineOffset() *because we so far have never needed them, 
> they are easy to get with the snappedXXX methods if needed.
>
> I am really hopping this will make it easy to maintain constant 
> behavior as we work on controls implementations in the futrure.
>
> Thanks
>
> Jasper