am eacfc308: am a0b259a9: am 161e423e: Merge "docs: Fixed deprecated value. Bug: 10641906" into jb-mr2-docs
* commit 'eacfc308344b34d27b7cd2ab8cc0fbdefbcc8167':
docs: Fixed deprecated value. Bug: 10641906
diff --git a/docs/html/guide/topics/ui/how-android-draws.jd b/docs/html/guide/topics/ui/how-android-draws.jd
index 6a8cd86..168f77b 100644
--- a/docs/html/guide/topics/ui/how-android-draws.jd
+++ b/docs/html/guide/topics/ui/how-android-draws.jd
@@ -4,15 +4,19 @@
@jd:body
-<p>When an Activity receives focus, it will be requested to draw its layout.
-The Android framework will handle the procedure for drawing, but the Activity must provide
+<p>When an {@link android.app.Activity} receives focus, it will be requested to
+draw its layout.
+The Android framework will handle the procedure for drawing, but the
+{@link android.app.Activity} must provide
the root node of its layout hierarchy.</p>
<p>Drawing begins with the root node of the layout. It is requested to measure and
-draw the layout tree. Drawing is handled by walking the tree and rendering each View that
- intersects the invalid region. In turn, each View group is responsible for requesting
-each of its children to be drawn (with the <code>{@link android.view.View#draw(Canvas) draw()}</code> method)
-and each View is responsible for drawing itself.
+draw the layout tree. Drawing is handled by walking the tree and rendering each
+{@link android.view.View} that intersects the invalid region. In turn, each
+{@link android.view.ViewGroup} is responsible for requesting
+each of its children to be drawn
+(with the {@link android.view.View#draw(Canvas) draw()} method)
+and each {@link android.view.View} is responsible for drawing itself.
Because the tree is traversed in-order,
this means that parents will be drawn before (i.e., behind) their children, with
siblings drawn in the order they appear in the tree.
@@ -20,76 +24,107 @@
<div class="sidebox-wrapper">
<div class="sidebox">
- <p>The framework will not draw Views that are not in the invalid region, and also
- will take care of drawing the Views background for you.</p>
- <p>You can force a View to draw, by calling <code>{@link android.view.View#invalidate()}</code>.
+ <p>The framework will not draw {@link android.view.View} objects that are not
+in the invalid region, and also
+ will take care of drawing the {@link android.view.View} background for you.</p>
+ <p>You can force a {@link android.view.View} to draw, by calling
+{@link android.view.View#invalidate()}.
</p>
</div>
</div>
<p>
- Drawing the layout is a two pass process: a measure pass and a layout pass. The measuring
- pass is implemented in <code>{@link android.view.View#measure(int, int)}</code> and is a top-down traversal
- of the View tree. Each View pushes dimension specifications down the tree
- during the recursion. At the end of the measure pass, every View has stored
+ Drawing the layout is a two pass process: a measure pass and a layout pass.
+The measuring pass is implemented in {@link android.view.View#measure(int, int)}
+and is a top-down traversal of the {@link android.view.View} tree. Each {@link android.view.View}
+pushes dimension specifications down the tree
+ during the recursion. At the end of the measure pass, every
+{@link android.view.View} has stored
its measurements. The second pass happens in
- <code>{@link android.view.View#layout(int,int,int,int)}</code> and is also top-down. During
+ {@link android.view.View#layout(int,int,int,int)} and is also top-down. During
this pass each parent is responsible for positioning all of its children
using the sizes computed in the measure pass.
</p>
<p>
- When a View's <code>measure()</code> method returns, its <code>{@link android.view.View#getMeasuredWidth()}</code> and
- <code>{@link android.view.View#getMeasuredHeight()}</code> values must be set, along with those for all of
- that View's descendants. A View's measured width and measured height values
- must respect the constraints imposed by the View's parents. This guarantees
+ When a {@link android.view.View} object's
+{@link android.view.View#measure(int, int) measure()} method
+returns, its {@link android.view.View#getMeasuredWidth()} and
+ {@link android.view.View#getMeasuredHeight()} values must be set, along
+ with those for all of that {@link android.view.View} object's descendants.
+A {@link android.view.View} object's measured width and
+measured height values must respect the constraints imposed by the
+{@link android.view.View} object's parents. This guarantees
that at the end of the measure pass, all parents accept all of their
- children's measurements. A parent View may call <code>measure()</code> more than once on
+ children's measurements. A parent {@link android.view.View} may call
+{@link android.view.View#measure(int, int) measure()} more than once on
its children. For example, the parent may measure each child once with
unspecified dimensions to find out how big they want to be, then call
- <code>measure()</code> on them again with actual numbers if the sum of all the children's
- unconstrained sizes is too big or too small (i.e., if the children don't agree among themselves
- as to how much space they each get, the parent will intervene and set the rules on the second pass).
+ {@link android.view.View#measure(int, int) measure()} on them again with
+actual numbers if the sum of all the children's
+ unconstrained sizes is too big or too small (that is, if the children
+don't agree among themselves
+ as to how much space they each get, the parent will intervene and set
+the rules on the second pass).
</p>
<div class="sidebox-wrapper">
<div class="sidebox"><p>
- To initiate a layout, call <code>{@link android.view.View#requestLayout}</code>. This method is typically
- called by a View on itself when it believes that is can no longer fit within
+ To initiate a layout, call {@link android.view.View#requestLayout}.
+This method is typically
+ called by a {@link android.view.View} on itself
+when it believes that is can no longer fit within
its current bounds.</p>
</div>
</div>
<p>
The measure pass uses two classes to communicate dimensions. The
- {@link android.view.ViewGroup.LayoutParams} class is used by Views to tell their parents how they
- want to be measured and positioned. The base LayoutParams class just
- describes how big the View wants to be for both width and height. For each
+ {@link android.view.ViewGroup.LayoutParams} class is used by
+{@link android.view.View} objects to tell their parents how they
+ want to be measured and positioned. The base
+{@link android.view.ViewGroup.LayoutParams} class just
+ describes how big the {@link android.view.View} wants to be for both
+width and height. For each
dimension, it can specify one of:</p>
<ul>
<li> an exact number
- <li><var>FILL_PARENT</var>, which means the View wants to be as big as its parent
+ <li>{@link android.view.ViewGroup.LayoutParams#MATCH_PARENT MATCH_PARENT},
+which means the {@link android.view.View} wants to be as big as its parent
(minus padding)</li>
- <li><var>WRAP_CONTENT</var>, which means that the View wants to be just big enough to
+ <li>{@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT WRAP_CONTENT},
+which means that the {@link android.view.View} wants to be just big enough to
enclose its content (plus padding).</li>
</ul>
- <p>There are subclasses of LayoutParams for different subclasses of ViewGroup.
- For example, RelativeLayout has its own subclass of LayoutParams, which includes
- the ability to center child Views horizontally and vertically.
+ <p>There are subclasses of {@link android.view.ViewGroup.LayoutParams} for
+different subclasses of {@link android.view.ViewGroup}.
+ For example, {@link android.widget.RelativeLayout} has its own subclass of
+{@link android.view.ViewGroup.LayoutParams}, which includes
+ the ability to center child {@link android.view.View} objects
+horizontally and vertically.
</p>
<p>
- MeasureSpecs are used to push requirements down the tree from parent to
- child. A MeasureSpec can be in one of three modes:</p>
+ {@link android.view.View.MeasureSpec MeasureSpec} objects are used to push
+requirements down the tree from parent to
+ child. A {@link android.view.View.MeasureSpec MeasureSpec} can be in one of
+three modes:</p>
<ul>
- <li><var>UNSPECIFIED</var>: This is used by a parent to determine the desired dimension
- of a child View. For example, a LinearLayout may call <code>measure()</code> on its child
- with the height set to <var>UNSPECIFIED</var> and a width of <var>EXACTLY</var> 240 to find out how
- tall the child View wants to be given a width of 240 pixels.</li>
- <li><var>EXACTLY</var>: This is used by the parent to impose an exact size on the
+ <li>{@link android.view.View.MeasureSpec#UNSPECIFIED UNSPECIFIED}: This is
+used by a parent to determine the desired dimension
+ of a child {@link android.view.View}. For example, a
+{@link android.widget.LinearLayout} may call
+{@link android.view.View#measure(int, int) measure()} on its child
+ with the height set to {@link android.view.View.MeasureSpec#UNSPECIFIED UNSPECIFIED}
+and a width of {@link android.view.View.MeasureSpec#EXACTLY EXACTLY} 240 to
+find out how tall the child {@link android.view.View} wants to be given a
+width of 240 pixels.</li>
+ <li>{@link android.view.View.MeasureSpec#EXACTLY EXACTLY}: This is used
+by the parent to impose an exact size on the
child. The child must use this size, and guarantee that all of its
descendants will fit within this size.</li>
- <li><var>AT_MOST</var>: This is used by the parent to impose a maximum size on the
+ <li>{@link android.view.View.MeasureSpec#AT_MOST AT MOST}: This is used by
+the parent to impose a maximum size on the
child. The child must guarantee that it and all of its descendants will fit
within this size.</li>
</ul>