/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.widget;
import android.content.Context;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
/**
* FrameLayout is designed to block out an area on the screen to display a
* single item. You can add multiple children to a FrameLayout, but all children
* are pegged to the top left of the screen. Children are drawn in a stack, with
* the most recently added child on top. The size of the frame layout is the
* size of its largest child (plus padding), visible or not (if the
* FrameLayout's parent permits). Views that are GONE are used for sizing only
* if {@link #setMeasureAllChildren(boolean)
* setConsiderGoneChildrenWhenMeasuring()} is set to true.
*
* @attr ref android.R.styleable#FrameLayout_foreground
* @attr ref android.R.styleable#FrameLayout_foregroundGravity
* @attr ref android.R.styleable#FrameLayout_measureAllChildren
*/
public class FrameLayout extends ViewGroup {
boolean mMeasureAllChildren = false;
private Drawable mForeground;
private int mForegroundPaddingLeft = 0;
private int mForegroundPaddingTop = 0;
private int mForegroundPaddingRight = 0;
private int mForegroundPaddingBottom = 0;
private final Rect mSelfBounds = new Rect();
private final Rect mOverlayBounds = new Rect();
private int mForegroundGravity = Gravity.FILL;
/** {@hide} */
protected boolean mForegroundInPadding = true;
boolean mForegroundBoundsChanged = false;
public FrameLayout(Context context) {
super(context);
initFrameLayout(context, null);
}
public FrameLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public FrameLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initFrameLayout(context, attrs);
}
private void initFrameLayout(Context c, AttributeSet attrs) {
if (attrs != null && attrs.getAttributeCount() > 0) {
parseFrameLayoutAttributes(attrs);
}
}
/**
* Describes how the foreground is positioned. Defaults to FILL.
*
* @param foregroundGravity
* See {@link android.view.Gravity}
*
* @attr ref android.R.styleable#FrameLayout_foregroundGravity
*/
public void setForegroundGravity(int foregroundGravity) {
if (mForegroundGravity != foregroundGravity) {
if ((foregroundGravity & Gravity.HORIZONTAL_GRAVITY_MASK) == 0) {
foregroundGravity |= Gravity.LEFT;
}
if ((foregroundGravity & Gravity.VERTICAL_GRAVITY_MASK) == 0) {
foregroundGravity |= Gravity.TOP;
}
mForegroundGravity = foregroundGravity;
if (mForegroundGravity == Gravity.FILL && mForeground != null) {
Rect padding = new Rect();
if (mForeground.getPadding(padding)) {
mForegroundPaddingLeft = padding.left;
mForegroundPaddingTop = padding.top;
mForegroundPaddingRight = padding.right;
mForegroundPaddingBottom = padding.bottom;
}
} else {
mForegroundPaddingLeft = 0;
mForegroundPaddingTop = 0;
mForegroundPaddingRight = 0;
mForegroundPaddingBottom = 0;
}
requestLayout();
}
}
/**
* {@inheritDoc}
*/
@Override
protected boolean verifyDrawable(Drawable who) {
return super.verifyDrawable(who) || (who == mForeground);
}
/**
* {@inheritDoc}
*/
@Override
protected void drawableStateChanged() {
super.drawableStateChanged();
if (mForeground != null && mForeground.isStateful()) {
mForeground.setState(getDrawableState());
}
}
/**
* Returns a set of layout parameters with a width of
* {@link android.view.ViewGroup.LayoutParams#FILL_PARENT}, and a height of
* {@link android.view.ViewGroup.LayoutParams#FILL_PARENT}.
*/
@Override
protected LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
}
/**
* Supply a Drawable that is to be rendered on top of all of the child views
* in the frame layout. Any padding in the Drawable will be taken into
* account by ensuring that the children are inset to be placed inside of
* the padding area.
*
* @param drawable
* The Drawable to be drawn on top of the children.
*
* @attr ref android.R.styleable#FrameLayout_foreground
*/
public void setForeground(Drawable drawable) {
if (mForeground != drawable) {
// if (mForeground != null) {
// mForeground.setCallback(null);
// unscheduleDrawable(mForeground);
// }
mForeground = drawable;
mForegroundPaddingLeft = 0;
mForegroundPaddingTop = 0;
mForegroundPaddingRight = 0;
mForegroundPaddingBottom = 0;
if (drawable != null) {
// setWillNotDraw(false);
// drawable.setCallback(this);
if (drawable.isStateful()) {
drawable.setState(getDrawableState());
}
if (mForegroundGravity == Gravity.FILL) {
Rect padding = new Rect();
if (drawable.getPadding(padding)) {
mForegroundPaddingLeft = padding.left;
mForegroundPaddingTop = padding.top;
mForegroundPaddingRight = padding.right;
mForegroundPaddingBottom = padding.bottom;
}
}
} else {
// setWillNotDraw(true);
}
requestLayout();
invalidate();
}
}
/**
* Returns the drawable used as the foreground of this FrameLayout. The
* foreground drawable, if non-null, is always drawn on top of the children.
*
* @return A Drawable or null if no foreground was set.
*/
public Drawable getForeground() {
return mForeground;
}
/**
* {@inheritDoc}
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
final int count = getChildCount();
int maxHeight = 0;
int maxWidth = 0;
// Find rightmost and bottommost child
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (mMeasureAllChildren || child.getVisibility() != GONE) {
measureChildWithMargins(child, widthMeasureSpec, 0, heightMeasureSpec, 0);
maxWidth = Math.max(maxWidth, child.getMeasuredWidth());
maxHeight = Math.max(maxHeight, child.getMeasuredHeight());
}
}
// Account for padding too
maxWidth += paddingLeft + paddingRight + mForegroundPaddingLeft + mForegroundPaddingRight;
maxHeight += paddingTop + paddingBottom + mForegroundPaddingTop + mForegroundPaddingBottom;
// Check against our minimum height and width
maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight());
maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());
// Check against our foreground's minimum height and width
final Drawable drawable = getForeground();
if (drawable != null) {
maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
}
setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec), resolveSize(maxHeight,
heightMeasureSpec));
}
/**
* {@inheritDoc}
*/
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
final int count = getChildCount();
final int parentLeft = paddingLeft + mForegroundPaddingLeft;
final int parentRight = right - left - paddingRight - mForegroundPaddingRight;
final int parentTop = paddingTop + mForegroundPaddingTop;
final int parentBottom = bottom - top - paddingBottom - mForegroundPaddingBottom;
mForegroundBoundsChanged = true;
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() != GONE) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final int width = child.getMeasuredWidth();
final int height = child.getMeasuredHeight();
int childLeft = parentLeft;
int childTop = parentTop;
final int gravity = lp.gravity;
if (gravity != -1) {
final int horizontalGravity = gravity & Gravity.HORIZONTAL_GRAVITY_MASK;
final int verticalGravity = gravity & Gravity.VERTICAL_GRAVITY_MASK;
switch (horizontalGravity) {
case Gravity.LEFT:
childLeft = parentLeft + lp.leftMargin;
break;
case Gravity.CENTER_HORIZONTAL:
childLeft = parentLeft
+ (parentRight - parentLeft + lp.leftMargin + lp.rightMargin - width)
/ 2;
break;
case Gravity.RIGHT:
childLeft = parentRight - width - lp.rightMargin;
break;
default:
childLeft = parentLeft + lp.leftMargin;
}
switch (verticalGravity) {
case Gravity.TOP:
childTop = parentTop + lp.topMargin;
break;
case Gravity.CENTER_VERTICAL:
childTop = parentTop
+ (parentBottom - parentTop + lp.topMargin + lp.bottomMargin - height)
/ 2;
break;
case Gravity.BOTTOM:
childTop = parentBottom - height - lp.bottomMargin;
break;
default:
childTop = parentTop + lp.topMargin;
}
}
child.layout(childLeft, childTop, childLeft + width, childTop + height);
}
}
}
/**
* {@inheritDoc}
*/
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mForegroundBoundsChanged = true;
}
/**
* {@inheritDoc}
*/
/*
* @Override public void draw(Canvas canvas) { super.draw(canvas);
*
* if (mForeground != null) { final Drawable foreground = mForeground;
*
* if (mForegroundBoundsChanged) { mForegroundBoundsChanged = false; final
* Rect selfBounds = mSelfBounds; final Rect overlayBounds = mOverlayBounds;
*
* final int w = getRight() - getLeft(); final int h = getBottom() -
* getTop();
*
* if (mForegroundInPadding) { selfBounds.set(0, 0, w, h); } else {
* selfBounds.set(paddingLeft, paddingTop, w - paddingRight, h -
* paddingBottom); }
*
* Gravity.apply(mForegroundGravity, foreground.getIntrinsicWidth(),
* foreground .getIntrinsicHeight(), selfBounds, overlayBounds);
* foreground.setBounds(overlayBounds); }
*
* foreground.draw(canvas); } }
*/
/**
* Determines whether to measure all children or just those in the VISIBLE
* or INVISIBLE state when measuring. Defaults to false.
*
* @param measureAll
* true to consider children marked GONE, false otherwise.
* Default value is false.
*
* @attr ref android.R.styleable#FrameLayout_measureAllChildren
*/
public void setMeasureAllChildren(boolean measureAll) {
mMeasureAllChildren = measureAll;
}
/**
* Determines whether to measure all children or just those in the VISIBLE
* or INVISIBLE state when measuring.
*/
public boolean getConsiderGoneChildrenWhenMeasuring() {
return mMeasureAllChildren;
}
/**
* {@inheritDoc}
*/
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new FrameLayout.LayoutParams(getContext(), attrs);
}
/**
* {@inheritDoc}
*/
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p instanceof LayoutParams;
}
@Override
protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
return new LayoutParams(p);
}
/**
* Per-child layout information for layouts that support margins. See
* {@link android.R.styleable#FrameLayout_Layout FrameLayout Layout
* Attributes} for a list of all child view attributes that this class
* supports.
*/
public static class LayoutParams extends MarginLayoutParams {
/**
* The gravity to apply with the View to which these layout parameters
* are associated.
*
* @see android.view.Gravity
*/
public int gravity = -1;
/**
* {@inheritDoc}
*/
public LayoutParams(Context c, AttributeSet attrs) {
super(c, attrs);
gravity = Gravity.parseGravity(attrs.getAttributeValue(null, "layout_gravity"), -1);
}
/**
* {@inheritDoc}
*/
public LayoutParams(int width, int height) {
super(width, height);
}
/**
* Creates a new set of layout parameters with the specified width,
* height and weight.
*
* @param width
* the width, either {@link #FILL_PARENT},
* {@link #WRAP_CONTENT} or a fixed size in pixels
* @param height
* the height, either {@link #FILL_PARENT},
* {@link #WRAP_CONTENT} or a fixed size in pixels
* @param gravity
* the gravity
*
* @see android.view.Gravity
*/
public LayoutParams(int width, int height, int gravity) {
super(width, height);
this.gravity = gravity;
}
/**
* {@inheritDoc}
*/
public LayoutParams(ViewGroup.LayoutParams source) {
super(source);
}
/**
* {@inheritDoc}
*/
public LayoutParams(ViewGroup.MarginLayoutParams source) {
super(source);
}
}
private void parseFrameLayoutAttributes(AttributeSet attrs) {
setIgnoreRequestLayout(true);
mForegroundGravity = Gravity.parseGravity(attrs
.getAttributeValue(null, "foregroundGravity"), Gravity.FILL);
String str = attrs.getAttributeValue(null, "background");
// Resolve foreground background
if (str != null) {
int foregroundId = attrs.getAttributeResourceValue(null, "foreground", -1);
if (foregroundId != -1) {
Drawable d = getContext().getResources().getDrawable(foregroundId);
if (d != null) {
setForeground(d);
}
}
}
boolean b = attrs.getAttributeBooleanValue(null, "measureAllChildren", false);
setMeasureAllChildren(b);
mForegroundInPadding = attrs
.getAttributeBooleanValue(null, "foregroundInsidePadding", true);
setIgnoreRequestLayout(false);
}
}