From 3d5f648f8fe61507107b900fc3c4cf79b19572c6 Mon Sep 17 00:00:00 2001 From: Dirk Dougherty Date: Thu, 25 Mar 2010 16:33:33 -0700 Subject: [PATCH] doc change: cherry pick 75c66da20927e7e854397c00ef1974140270c57f. (clarify fill_parent/match_parent transition in ViewGroup.LayoutParams and R.attr. Mention match_parent in dev guide "declaring layout" doc.) Change-Id: I1d2b80b8dc3f8b2e3c1befcbb7c4c522d78a2db8 --- core/java/android/view/ViewGroup.java | 40 ++++++++++------- core/res/res/values/attrs.xml | 44 ++++++++++++------- docs/html/guide/topics/ui/declaring-layout.jd | 32 ++++++++++---- 3 files changed, 76 insertions(+), 40 deletions(-) diff --git a/core/java/android/view/ViewGroup.java b/core/java/android/view/ViewGroup.java index 006aff896223a..eca583f46b221 100644 --- a/core/java/android/view/ViewGroup.java +++ b/core/java/android/view/ViewGroup.java @@ -3457,11 +3457,11 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager * The base LayoutParams class just describes how big the view wants to be * for both width and height. For each dimension, it can specify one of: * * There are subclasses of LayoutParams for different subclasses of * ViewGroup. For example, AbsoluteLayout has its own subclass of @@ -3472,8 +3472,10 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager */ public static class LayoutParams { /** - * This value has the same meaning as {@link #MATCH_PARENT} but has - * been deprecated. + * Special value for the height or width requested by a View. + * FILL_PARENT means that the view wants to be as big as its parent, + * minus the parent's padding, if any. This value is deprecated + * starting in API Level 8 and replaced by {@link #MATCH_PARENT}. */ @SuppressWarnings({"UnusedDeclaration"}) @Deprecated @@ -3482,7 +3484,7 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager /** * Special value for the height or width requested by a View. * MATCH_PARENT means that the view wants to be as big as its parent, - * minus the parent's padding, if any. + * minus the parent's padding, if any. Introduced in API Level 8. */ public static final int MATCH_PARENT = -1; @@ -3494,8 +3496,9 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager public static final int WRAP_CONTENT = -2; /** - * Information about how wide the view wants to be. Can be an exact - * size, or one of the constants MATCH_PARENT or WRAP_CONTENT. + * Information about how wide the view wants to be. Can be one of the + * constants FILL_PARENT (replaced by MATCH_PARENT , + * in API Level 8) or WRAP_CONTENT. or an exact size. */ @ViewDebug.ExportedProperty(mapping = { @ViewDebug.IntToString(from = MATCH_PARENT, to = "MATCH_PARENT"), @@ -3504,8 +3507,9 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager public int width; /** - * Information about how tall the view wants to be. Can be an exact - * size, or one of the constants MATCH_PARENT or WRAP_CONTENT. + * Information about how tall the view wants to be. Can be one of the + * constants FILL_PARENT (replaced by MATCH_PARENT , + * in API Level 8) or WRAP_CONTENT. or an exact size. */ @ViewDebug.ExportedProperty(mapping = { @ViewDebug.IntToString(from = MATCH_PARENT, to = "MATCH_PARENT"), @@ -3525,9 +3529,11 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager * * * * @param c the application environment @@ -3546,10 +3552,12 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager * Creates a new set of layout parameters with the specified width * and height. * - * @param width the width, either {@link #MATCH_PARENT}, - * {@link #WRAP_CONTENT} or a fixed size in pixels - * @param height the height, either {@link #MATCH_PARENT}, - * {@link #WRAP_CONTENT} or a fixed size in pixels + * @param width the width, either {@link #WRAP_CONTENT}, + * {@link #FILL_PARENT} (replaced by {@link #MATCH_PARENT} in + * API Level 8), or a fixed size in pixels + * @param height the height, either {@link #WRAP_CONTENT}, + * {@link #FILL_PARENT} (replaced by {@link #MATCH_PARENT} in + * API Level 8), or a fixed size in pixels */ public LayoutParams(int width, int height) { this.width = width; diff --git a/core/res/res/values/attrs.xml b/core/res/res/values/attrs.xml index 24808ec7217ea..16b241bed7bd4 100644 --- a/core/res/res/values/attrs.xml +++ b/core/res/res/values/attrs.xml @@ -1396,9 +1396,12 @@ be a dimension (such as "12dip") for a constant width or one of the special constants. --> - + - + @@ -1409,9 +1412,12 @@ be a dimension (such as "12dip") for a constant height or one of the special constants. --> - + - + @@ -2128,27 +2134,35 @@ is used. --> + be a dimension (such as "12dip") for a constant width, + fill_parent or match_parent to match the width of the + screen, or wrap_content to match the width of + the anchored view. --> - + - + - - + - + - + diff --git a/docs/html/guide/topics/ui/declaring-layout.jd b/docs/html/guide/topics/ui/declaring-layout.jd index f114895c87a96..5c12db9f4ded8 100644 --- a/docs/html/guide/topics/ui/declaring-layout.jd +++ b/docs/html/guide/topics/ui/declaring-layout.jd @@ -200,15 +200,29 @@ view group defines layout parameters for each child view (including the child vi values. Each child element must define LayoutParams that are appropriate for its parent, though it may also define different LayoutParams for its own children.

-

All view groups include a width and height (layout_width and layout_height), -and each view is required to define them. -Many LayoutParams also include optional margins and -borders. You can specify width and height with exact measurements, though you probably won't want -to do this often. More often, you will tell your view to size itself either to -the dimensions required by its content, or to become as big as its parent view group -will allow (with the wrap_content and fill_parent values, respectively). -The accepted measurement types are defined in the -Available Resources document.

+

All view groups include a width and height (layout_width and +layout_height), and each view is required to define them. Many +LayoutParams also include optional margins and borders.

+ +

You can specify width and height with exact measurements, though you probably +won't want to do this often. More often, you will use one of these constants to +set the width or height:

+ +
    +
  • wrap_content tells your view to size itself to the dimensions +required by its content
    • +
  • fill_parent (renamed match_parent in API Level 8) +tells your view to become as big as its parent view group will allow.
    • +
+ +

In general, specifying a layout width and height using absolute units such as +pixels is not recommended. Instead, using relative measurements such as +density-independent pixel units (dp), wrap_content, or +fill_parent, is a better approach, because it helps ensure that +your application will display properly across a variety of device screen sizes. +The accepted measurement types are defined in the + +Available Resources document.

Layout Position