# Tab Stop Policy Andy Goryachev
<andy.goryac...@oracle.com> ## Summary Introduce a `tabStopPolicy` property in the `TextFlow` class which, when set, overrides the existing `tabSize` value and provides consistent way of setting tab stops at the paragraph level, regardless of the individual text segments font [0].  ## Goals The goal of this proposal is to provide a better way for controlling tab stops in the `TextFlow` containing rich text. ## Non-Goals The following are not the goals of this proposal: - support for tab stop types (BAR, or DECIMAL), or attributes like `alignment` - support the `leader` property (symbols to fill the empty space before the tab stop) - support for `firstLineIndent` property - deprecate the `TextFlow::tabsize` property ## Motivation The existing `tabSize` property in the `TextFlow` is inadequate for representing tab stops when the content contains text with different font sizes. In addition to that, a rich text editor might require support for user-customizable tab stops, similar to that provided in RTF or MS Word documents. ## Description ### TextFlow /** * {@code TabAdvancePolicy} determines the tab stop positions within this {@code TextFlow}. * <p> * A non-null {@code TabAdvancePolicy} overrides values set by {@link #setTabSize(int)}, * as well as any values set by {@link Text#setTabSize(int)} in individual {@code Text} instances within * this {@code TextFlow}. * * @defaultValue null * * @since 999 TODO */ public final ObjectProperty<TabStopPolicy> tabStopPolicyProperty() { public final TabStopPolicy getTabStopPolicy() { public final void setTabStopPolicy(TabStopPolicy policy) { /** * The size of a tab stop in spaces. * Values less than 1 are treated as 1. This value overrides the * {@code tabSize} of contained {@link Text} nodes. * <p> + * Note that this method should not be used to control the tab placement when multiple {@code Text} nodes + * with different fonts are contained within this {@code TextFlow}. + * In this case, the {@link #setTabStopPolicy(TabStopPolicy)} should be used instead. * * @defaultValue 8 * * @since 14 */ public final IntegerProperty tabSizeProperty() { ### TabStopPolicy /** * The TabStopPolicy determines the tab stop positions within the text layout. * * @since 999 TODO */ public class TabStopPolicy { /** * Constructs a new {@code TabStopPolicy} instance. */ public TabStopPolicy() { /** * Specifies the unmodifiable list of tab stops, sorted by position from smallest to largest. * The list can be changed using * * @return the non-null, unmodifiable list of tab stops, sorted by position */ public final ObservableList<TabStop> tabStops() { /** * Provides default tab stops (beyond the last tab stop specified by {@code #tabStops()}, * as a fixed repeating distance in pixels from the last tab stop position. * The position of default tab stops is computed at regular intervals relative to * the leading edge of the {@code TextFlow} this policy is registered with. * <p> * The value of less than or equal 0 disables the default stops. * * @return the default tab stops property * @defaultValue 0 */ public final DoubleProperty defaultStopsProperty() { public final double getDefaultStops() { public final void setDefaultStops(double value) { ### TabStop /** * This class encapsulates an immutable single tab stop within the {@link TabStopPolicy}. * <p> * A tab stop is at a specified distance from the * left margin, aligns text in a specified way, and has a specified leader. * * @since 999 TODO */ public class TabStop { /** * Constructs a new tab stop with the specified position. * * @param position the position in pixels */ public TabStop(double position) { /** * Returns the position, in pixels, of the tab. * @return the position of the tab */ public final double getPosition() { ## Alternatives None known. ## Risks and Assumptions Possible incompatibility with custom controls which extend `TextFlow` and declare a property with the same name. ## Dependencies None. ## References 0. [JDK-8314482](https://bugs.openjdk.org/browse/JDK-8314482) 1. https://github.com/andy-goryachev-oracle/Test/blob/main/doc/TabStopPolicy/TabStopPolicy.md ------------- Commit messages: - cleanup - api - Merge remote-tracking branch 'origin/master' into 8314482.tab.stops - cleanup - Merge remote-tracking branch 'origin/master' into 8314482.tab.stops - seems to work - wired - moved - Merge remote-tracking branch 'origin/master' into 8314482.tab.stops - local to scene - ... and 45 more: https://git.openjdk.org/jfx/compare/3299949c...d624df53 Changes: https://git.openjdk.org/jfx/pull/1744/files Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1744&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8314482 Stats: 658 lines in 12 files changed: 592 ins; 37 del; 29 mod Patch: https://git.openjdk.org/jfx/pull/1744.diff Fetch: git fetch https://git.openjdk.org/jfx.git pull/1744/head:pull/1744 PR: https://git.openjdk.org/jfx/pull/1744
