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Merge "Correctly distribute weight to pre-measured zero-dimension views"

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This commit is contained in:
Alan Viverette
2015-08-25 21:19:41 +00:00
committed by Android (Google) Code Review
parent e3e7b52324 40e1df34a9
commit 4e64974998
1 changed files with 108 additions and 112 deletions
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220
core/java/android/widget/LinearLayout.java
View File

@@ -25,6 +25,7 @@ import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
@@ -98,6 +99,13 @@ public class LinearLayout extends ViewGroup {
*/
public static final int SHOW_DIVIDER_END = 4;
/**
* Compatibility check. Old versions of the platform would give different
* results from measurement passes using EXACTLY and non-EXACTLY modes,
* even when the resulting size was the same.
*/
private final boolean mAllowInconsistentMeasurement;
/**
* Whether the children of this layout are baseline aligned. Only applicable
* if {@link #mOrientation} is horizontal.
@@ -231,6 +239,9 @@ public class LinearLayout extends ViewGroup {
mShowDividers = a.getInt(R.styleable.LinearLayout_showDividers, SHOW_DIVIDER_NONE);
mDividerPadding = a.getDimensionPixelSize(R.styleable.LinearLayout_dividerPadding, 0);
final int version = context.getApplicationInfo().targetSdkVersion;
mAllowInconsistentMeasurement = version <= Build.VERSION_CODES.M;
a.recycle();
}
@@ -699,6 +710,7 @@ public class LinearLayout extends ViewGroup {
final boolean useLargestChild = mUseLargestChild;
int largestChildHeight = Integer.MIN_VALUE;
int consumedExcessSpace = 0;
// See how tall everyone is. Also remember max width.
for (int i = 0; i < count; ++i) {
@@ -718,26 +730,25 @@ public class LinearLayout extends ViewGroup {
mTotalLength += mDividerHeight;
}
LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) child.getLayoutParams();
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
totalWeight += lp.weight;
if (heightMode == MeasureSpec.EXACTLY && lp.height == 0 && lp.weight > 0) {
// Optimization: don't bother measuring children who are going to use
// leftover space. These views will get measured again down below if
// there is any leftover space.
final boolean useExcessSpace = lp.height == 0 && lp.weight > 0;
if (heightMode == MeasureSpec.EXACTLY && useExcessSpace) {
// Optimization: don't bother measuring children who are only
// laid out using excess space. These views will get measured
// later if we have space to distribute.
final int totalLength = mTotalLength;
mTotalLength = Math.max(totalLength, totalLength + lp.topMargin + lp.bottomMargin);
skippedMeasure = true;
} else {
int oldHeight = Integer.MIN_VALUE;
if (lp.height == 0 && lp.weight > 0) {
// heightMode is either UNSPECIFIED or AT_MOST, and this
// child wanted to stretch to fill available space.
// Translate that to WRAP_CONTENT so that it does not end up
// with a height of 0
oldHeight = 0;
if (useExcessSpace) {
// The heightMode is either UNSPECIFIED or AT_MOST, and
// this child is only laid out using excess space. Measure
// using WRAP_CONTENT so that we can find out the view's
// optimal height. We'll restore the original height of 0
// after measurement.
lp.height = LayoutParams.WRAP_CONTENT;
}
@@ -745,15 +756,19 @@ public class LinearLayout extends ViewGroup {
// previous children have given a weight, then we allow it to
// use all available space (and we will shrink things later
// if needed).
measureChildBeforeLayout(
child, i, widthMeasureSpec, 0, heightMeasureSpec,
totalWeight == 0 ? mTotalLength : 0);
if (oldHeight != Integer.MIN_VALUE) {
lp.height = oldHeight;
}
final int usedHeight = totalWeight == 0 ? mTotalLength : 0;
measureChildBeforeLayout(child, i, widthMeasureSpec, 0,
heightMeasureSpec, usedHeight);
final int childHeight = child.getMeasuredHeight();
if (useExcessSpace) {
// Restore the original height and record how much space
// we've allocated to excess-only children so that we can
// match the behavior of EXACTLY measurement.
lp.height = 0;
consumedExcessSpace += childHeight;
}
final int totalLength = mTotalLength;
mTotalLength = Math.max(totalLength, totalLength + childHeight + lp.topMargin +
lp.bottomMargin + getNextLocationOffset(child));
@@ -857,52 +872,42 @@ public class LinearLayout extends ViewGroup {
// Either expand children with weight to take up available space or
// shrink them if they extend beyond our current bounds. If we skipped
// measurement on any children, we need to measure them now.
int delta = heightSize - mTotalLength;
final int delta = heightSize - mTotalLength
+ (mAllowInconsistentMeasurement ? 0 : consumedExcessSpace);
if (skippedMeasure || delta != 0 && totalWeight > 0.0f) {
float weightSum = mWeightSum > 0.0f ? mWeightSum : totalWeight;
final float weightSum = mWeightSum > 0.0f ? mWeightSum : totalWeight;
mTotalLength = 0;
for (int i = 0; i < count; ++i) {
final View child = getVirtualChildAt(i);
if (child.getVisibility() == View.GONE) {
if (child == null || child.getVisibility() == View.GONE) {
continue;
}
LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) child.getLayoutParams();
float childExtra = lp.weight;
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final float childExtra = lp.weight;
if (childExtra > 0) {
// Child said it could absorb extra space -- give him his share
int share = (int) (childExtra * delta / weightSum);
weightSum -= childExtra;
delta -= share;
final int childWidthMeasureSpec = getChildMeasureSpec(widthMeasureSpec,
mPaddingLeft + mPaddingRight +
lp.leftMargin + lp.rightMargin, lp.width);
// TODO: Use a field like lp.isMeasured to figure out if this
// child has been previously measured
if ((lp.height != 0) || (heightMode != MeasureSpec.EXACTLY)) {
// child was measured once already above...
// base new measurement on stored values
int childHeight = child.getMeasuredHeight() + share;
if (childHeight < 0) {
childHeight = 0;
}
child.measure(childWidthMeasureSpec,
MeasureSpec.makeMeasureSpec(childHeight, MeasureSpec.EXACTLY));
final int share = (int) (childExtra * delta / weightSum);
final int childHeight;
if (lp.height == 0 && (!mAllowInconsistentMeasurement
|| heightMode == MeasureSpec.EXACTLY)) {
// This child needs to be laid out from scratch using
// only its share of excess space.
childHeight = share;
} else {
// child was skipped in the loop above.
// Measure for this first time here
child.measure(childWidthMeasureSpec,
MeasureSpec.makeMeasureSpec(share > 0 ? share : 0,
MeasureSpec.EXACTLY));
// This child had some intrinsic height to which we
// need to add its share of excess space.
childHeight = child.getMeasuredHeight() + share;
}
final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
Math.max(0, childHeight), MeasureSpec.EXACTLY);
final int childWidthMeasureSpec = getChildMeasureSpec(widthMeasureSpec,
mPaddingLeft + mPaddingRight + lp.leftMargin + lp.rightMargin,
lp.width);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
// Child may now not fit in vertical dimension.
childState = combineMeasuredStates(childState, child.getMeasuredState()
& (MEASURED_STATE_MASK>>MEASURED_HEIGHT_STATE_SHIFT));
@@ -1043,6 +1048,7 @@ public class LinearLayout extends ViewGroup {
final boolean isExactly = widthMode == MeasureSpec.EXACTLY;
int largestChildWidth = Integer.MIN_VALUE;
int usedExcessSpace = 0;
// See how wide everyone is. Also remember max height.
for (int i = 0; i < count; ++i) {
@@ -1062,15 +1068,15 @@ public class LinearLayout extends ViewGroup {
mTotalLength += mDividerWidth;
}
final LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams)
child.getLayoutParams();
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
totalWeight += lp.weight;
if (widthMode == MeasureSpec.EXACTLY && lp.width == 0 && lp.weight > 0) {
// Optimization: don't bother measuring children who are going to use
// leftover space. These views will get measured again down below if
// there is any leftover space.
final boolean useExcessSpace = lp.width == 0 && lp.weight > 0;
if (widthMode == MeasureSpec.EXACTLY && useExcessSpace) {
// Optimization: don't bother measuring children who are only
// laid out using excess space. These views will get measured
// later if we have space to distribute.
if (isExactly) {
mTotalLength += lp.leftMargin + lp.rightMargin;
} else {
@@ -1094,14 +1100,12 @@ public class LinearLayout extends ViewGroup {
skippedMeasure = true;
}
} else {
int oldWidth = Integer.MIN_VALUE;
if (lp.width == 0 && lp.weight > 0) {
// widthMode is either UNSPECIFIED or AT_MOST, and this
// child
// wanted to stretch to fill available space. Translate that to
// WRAP_CONTENT so that it does not end up with a width of 0
oldWidth = 0;
if (useExcessSpace) {
// The widthMode is either UNSPECIFIED or AT_MOST, and
// this child is only laid out using excess space. Measure
// using WRAP_CONTENT so that we can find out the view's
// optimal width. We'll restore the original width of 0
// after measurement.
lp.width = LayoutParams.WRAP_CONTENT;
}
@@ -1109,22 +1113,26 @@ public class LinearLayout extends ViewGroup {
// previous children have given a weight, then we allow it to
// use all available space (and we will shrink things later
// if needed).
measureChildBeforeLayout(child, i, widthMeasureSpec,
totalWeight == 0 ? mTotalLength : 0,
final int usedWidth = totalWeight == 0 ? mTotalLength : 0;
measureChildBeforeLayout(child, i, widthMeasureSpec, usedWidth,
heightMeasureSpec, 0);
if (oldWidth != Integer.MIN_VALUE) {
lp.width = oldWidth;
final int childWidth = child.getMeasuredWidth();
if (useExcessSpace) {
// Restore the original width and record how much space
// we've allocated to excess-only children so that we can
// match the behavior of EXACTLY measurement.
lp.width = 0;
usedExcessSpace += childWidth;
}
final int childWidth = child.getMeasuredWidth();
if (isExactly) {
mTotalLength += childWidth + lp.leftMargin + lp.rightMargin +
getNextLocationOffset(child);
mTotalLength += childWidth + lp.leftMargin + lp.rightMargin
+ getNextLocationOffset(child);
} else {
final int totalLength = mTotalLength;
mTotalLength = Math.max(totalLength, totalLength + childWidth + lp.leftMargin +
lp.rightMargin + getNextLocationOffset(child));
mTotalLength = Math.max(totalLength, totalLength + childWidth + lp.leftMargin
+ lp.rightMargin + getNextLocationOffset(child));
}
if (useLargestChild) {
@@ -1242,9 +1250,10 @@ public class LinearLayout extends ViewGroup {
// Either expand children with weight to take up available space or
// shrink them if they extend beyond our current bounds. If we skipped
// measurement on any children, we need to measure them now.
int delta = widthSize - mTotalLength;
final int delta = widthSize - mTotalLength
+ (mAllowInconsistentMeasurement ? 0 : usedExcessSpace);
if (skippedMeasure || delta != 0 && totalWeight > 0.0f) {
float weightSum = mWeightSum > 0.0f ? mWeightSum : totalWeight;
final float weightSum = mWeightSum > 0.0f ? mWeightSum : totalWeight;
maxAscent[0] = maxAscent[1] = maxAscent[2] = maxAscent[3] = -1;
maxDescent[0] = maxDescent[1] = maxDescent[2] = maxDescent[3] = -1;
@@ -1254,45 +1263,32 @@ public class LinearLayout extends ViewGroup {
for (int i = 0; i < count; ++i) {
final View child = getVirtualChildAt(i);
if (child == null || child.getVisibility() == View.GONE) {
continue;
}
final LinearLayout.LayoutParams lp =
(LinearLayout.LayoutParams) child.getLayoutParams();
float childExtra = lp.weight;
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final float childExtra = lp.weight;
if (childExtra > 0) {
// Child said it could absorb extra space -- give him his share
int share = (int) (childExtra * delta / weightSum);
weightSum -= childExtra;
delta -= share;
final int share = (int) (childExtra * delta / weightSum);
final int childWidth;
if (lp.width == 0 && (!mAllowInconsistentMeasurement
|| widthMode == MeasureSpec.EXACTLY)) {
// This child needs to be laid out from scratch using
// only its share of excess space.
childWidth = share;
} else {
// This child had some intrinsic width to which we
// need to add its share of excess space.
childWidth = child.getMeasuredWidth() + share;
}
final int childHeightMeasureSpec = getChildMeasureSpec(
heightMeasureSpec,
final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
Math.max(0, childWidth), MeasureSpec.EXACTLY);
final int childHeightMeasureSpec = getChildMeasureSpec(heightMeasureSpec,
mPaddingTop + mPaddingBottom + lp.topMargin + lp.bottomMargin,
lp.height);
// TODO: Use a field like lp.isMeasured to figure out if this
// child has been previously measured
if ((lp.width != 0) || (widthMode != MeasureSpec.EXACTLY)) {
// child was measured once already above ... base new measurement
// on stored values
int childWidth = child.getMeasuredWidth() + share;
if (childWidth < 0) {
childWidth = 0;
}
child.measure(
MeasureSpec.makeMeasureSpec(childWidth, MeasureSpec.EXACTLY),
childHeightMeasureSpec);
} else {
// child was skipped in the loop above. Measure for this first time here
child.measure(MeasureSpec.makeMeasureSpec(
share > 0 ? share : 0, MeasureSpec.EXACTLY),
childHeightMeasureSpec);
}
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
// Child may now not fit in horizontal dimension.
childState = combineMeasuredStates(childState,