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Diffstat (limited to 'core/java/android/widget/LinearLayout.java')
| -rw-r--r-- | core/java/android/widget/LinearLayout.java | 1315 |
1 files changed, 1315 insertions, 0 deletions
diff --git a/core/java/android/widget/LinearLayout.java b/core/java/android/widget/LinearLayout.java new file mode 100644 index 0000000..de74fa4 --- /dev/null +++ b/core/java/android/widget/LinearLayout.java @@ -0,0 +1,1315 @@ +/* + * 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.content.res.TypedArray; +import android.util.AttributeSet; +import android.view.Gravity; +import android.view.View; +import android.view.ViewDebug; +import android.view.ViewGroup; +import android.widget.RemoteViews.RemoteView; + +import com.android.internal.R; + + +/** + * A Layout that arranges its children in a single column or a single row. The direction of + * the row can be set by calling {@link #setOrientation(int) setOrientation()}. + * You can also specify gravity, which specifies the alignment of all the child elements by + * calling {@link #setGravity(int) setGravity()} or specify that specific children + * grow to fill up any remaining space in the layout by setting the <em>weight</em> member of + * {@link android.widget.LinearLayout.LayoutParams LinearLayout.LayoutParams}. + * The default orientation is horizontal. + * + * <p> + * Also see {@link LinearLayout.LayoutParams android.widget.LinearLayout.LayoutParams} + * for layout attributes </p> + */ +@RemoteView +public class LinearLayout extends ViewGroup { + public static final int HORIZONTAL = 0; + public static final int VERTICAL = 1; + + /** + * Whether the children of this layout are baseline aligned. Only applicable + * if {@link #mOrientation} is horizontal. + */ + private boolean mBaselineAligned = true; + + /** + * If this layout is part of another layout that is baseline aligned, + * use the child at this index as the baseline. + * + * Note: this is orthogonal to {@link #mBaselineAligned}, which is concerned + * with whether the children of this layout are baseline aligned. + */ + private int mBaselineAlignedChildIndex = 0; + + /** + * The additional offset to the child's baseline. + * We'll calculate the baseline of this layout as we measure vertically; for + * horizontal linear layouts, the offset of 0 is appropriate. + */ + private int mBaselineChildTop = 0; + + private int mOrientation; + private int mGravity = Gravity.LEFT | Gravity.TOP; + private int mTotalLength; + + private float mWeightSum; + + private int[] mMaxAscent; + private int[] mMaxDescent; + + private static final int VERTICAL_GRAVITY_COUNT = 4; + + private static final int INDEX_CENTER_VERTICAL = 0; + private static final int INDEX_TOP = 1; + private static final int INDEX_BOTTOM = 2; + private static final int INDEX_FILL = 3; + + public LinearLayout(Context context) { + super(context); + } + + public LinearLayout(Context context, AttributeSet attrs) { + super(context, attrs); + + TypedArray a = + context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.LinearLayout); + + int index = a.getInt(com.android.internal.R.styleable.LinearLayout_orientation, -1); + if (index >= 0) { + setOrientation(index); + } + + index = a.getInt(com.android.internal.R.styleable.LinearLayout_gravity, -1); + if (index >= 0) { + setGravity(index); + } + + boolean baselineAligned = a.getBoolean(R.styleable.LinearLayout_baselineAligned, true); + if (!baselineAligned) { + setBaselineAligned(baselineAligned); + } + + mWeightSum = a.getFloat(R.styleable.LinearLayout_weightSum, -1.0f); + + mBaselineAlignedChildIndex = + a.getInt(com.android.internal.R.styleable.LinearLayout_baselineAlignedChildIndex, -1); + + a.recycle(); + } + + /** + * <p>Indicates whether widgets contained within this layout are aligned + * on their baseline or not.</p> + * + * @return true when widgets are baseline-aligned, false otherwise + */ + public boolean isBaselineAligned() { + return mBaselineAligned; + } + + /** + * <p>Defines whether widgets contained in this layout are + * baseline-aligned or not.</p> + * + * @param baselineAligned true to align widgets on their baseline, + * false otherwise + * + * @attr ref android.R.styleable#LinearLayout_baselineAligned + */ + public void setBaselineAligned(boolean baselineAligned) { + mBaselineAligned = baselineAligned; + } + + @Override + public int getBaseline() { + if (mBaselineAlignedChildIndex < 0) { + return super.getBaseline(); + } + + if (getChildCount() <= mBaselineAlignedChildIndex) { + throw new RuntimeException("mBaselineAlignedChildIndex of LinearLayout " + + "set to an index that is out of bounds."); + } + + final View child = getChildAt(mBaselineAlignedChildIndex); + final int childBaseline = child.getBaseline(); + + if (childBaseline == -1) { + if (mBaselineAlignedChildIndex == 0) { + // this is just the default case, safe to return -1 + return -1; + } + // the user picked an index that points to something that doesn't + // know how to calculate its baseline. + throw new RuntimeException("mBaselineAlignedChildIndex of LinearLayout " + + "points to a View that doesn't know how to get its baseline."); + } + + // TODO: This should try to take into account the virtual offsets + // (See getNextLocationOffset and getLocationOffset) + // We should add to childTop: + // sum([getNextLocationOffset(getChildAt(i)) / i < mBaselineAlignedChildIndex]) + // and also add: + // getLocationOffset(child) + int childTop = mBaselineChildTop; + + if (mOrientation == VERTICAL) { + final int majorGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; + if (majorGravity != Gravity.TOP) { + switch (majorGravity) { + case Gravity.BOTTOM: + childTop = mBottom - mTop - mPaddingBottom - mTotalLength; + break; + + case Gravity.CENTER_VERTICAL: + childTop += ((mBottom - mTop - mPaddingTop - mPaddingBottom) - + mTotalLength) / 2; + break; + } + } + } + + LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) child.getLayoutParams(); + return childTop + lp.topMargin + childBaseline; + } + + /** + * @return The index of the child that will be used if this layout is + * part of a larger layout that is baseline aligned, or -1 if none has + * been set. + */ + public int getBaselineAlignedChildIndex() { + return mBaselineAlignedChildIndex; + } + + /** + * @param i The index of the child that will be used if this layout is + * part of a larger layout that is baseline aligned. + * + * @attr ref android.R.styleable#LinearLayout_baselineAlignedChildIndex + */ + public void setBaselineAlignedChildIndex(int i) { + if ((i < 0) || (i >= getChildCount())) { + throw new IllegalArgumentException("base aligned child index out " + + "of range (0, " + getChildCount() + ")"); + } + mBaselineAlignedChildIndex = i; + } + + /** + * <p>Returns the view at the specified index. This method can be overriden + * to take into account virtual children. Refer to + * {@link android.widget.TableLayout} and {@link android.widget.TableRow} + * for an example.</p> + * + * @param index the child's index + * @return the child at the specified index + */ + View getVirtualChildAt(int index) { + return getChildAt(index); + } + + /** + * <p>Returns the virtual number of children. This number might be different + * than the actual number of children if the layout can hold virtual + * children. Refer to + * {@link android.widget.TableLayout} and {@link android.widget.TableRow} + * for an example.</p> + * + * @return the virtual number of children + */ + int getVirtualChildCount() { + return getChildCount(); + } + + /** + * Returns the desired weights sum. + * + * @return A number greater than 0.0f if the weight sum is defined, or + * a number lower than or equals to 0.0f if not weight sum is + * to be used. + */ + public float getWeightSum() { + return mWeightSum; + } + + /** + * Defines the desired weights sum. If unspecified the weights sum is computed + * at layout time by adding the layout_weight of each child. + * + * This can be used for instance to give a single child 50% of the total + * available space by giving it a layout_weight of 0.5 and setting the + * weightSum to 1.0. + * + * @param weightSum a number greater than 0.0f, or a number lower than or equals + * to 0.0f if the weight sum should be computed from the children's + * layout_weight + */ + public void setWeightSum(float weightSum) { + mWeightSum = Math.max(0.0f, weightSum); + } + + @Override + protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { + if (mOrientation == VERTICAL) { + measureVertical(widthMeasureSpec, heightMeasureSpec); + } else { + measureHorizontal(widthMeasureSpec, heightMeasureSpec); + } + } + + /** + * Measures the children when the orientation of this LinearLayout is set + * to {@link #VERTICAL}. + * + * @param widthMeasureSpec Horizontal space requirements as imposed by the parent. + * @param heightMeasureSpec Vertical space requirements as imposed by the parent. + * + * @see #getOrientation() + * @see #setOrientation(int) + * @see #onMeasure(int, int) + */ + void measureVertical(int widthMeasureSpec, int heightMeasureSpec) { + mTotalLength = 0; + int maxWidth = 0; + int alternativeMaxWidth = 0; + int weightedMaxWidth = 0; + boolean allFillParent = true; + float totalWeight = 0; + + final int count = getVirtualChildCount(); + + final int widthMode = MeasureSpec.getMode(widthMeasureSpec); + final int heightMode = MeasureSpec.getMode(heightMeasureSpec); + + boolean matchWidth = false; + + final int baselineChildIndex = mBaselineAlignedChildIndex; + + // See how tall everyone is. Also remember max width. + for (int i = 0; i < count; ++i) { + final View child = getVirtualChildAt(i); + + if (child == null) { + mTotalLength += measureNullChild(i); + continue; + } + + if (child.getVisibility() == View.GONE) { + i += getChildrenSkipCount(child, i); + continue; + } + + LinearLayout.LayoutParams lp = (LinearLayout.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. + mTotalLength += lp.topMargin + lp.bottomMargin; + } 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 = lp.height; + lp.height = LayoutParams.WRAP_CONTENT; + } + + // Determine how big this child would like to. If this or + // 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; + } + + mTotalLength += child.getMeasuredHeight() + lp.topMargin + + lp.bottomMargin + getNextLocationOffset(child); + } + + /** + * If applicable, compute the additional offset to the child's baseline + * we'll need later when asked {@link #getBaseline}. + */ + if ((baselineChildIndex >= 0) && (baselineChildIndex == i + 1)) { + mBaselineChildTop = mTotalLength; + } + + // if we are trying to use a child index for our baseline, the above + // book keeping only works if there are no children above it with + // weight. fail fast to aid the developer. + if (i < baselineChildIndex && lp.weight > 0) { + throw new RuntimeException("A child of LinearLayout with index " + + "less than mBaselineAlignedChildIndex has weight > 0, which " + + "won't work. Either remove the weight, or don't set " + + "mBaselineAlignedChildIndex."); + } + + boolean matchWidthLocally = false; + if (widthMode != MeasureSpec.EXACTLY && lp.width == LayoutParams.FILL_PARENT) { + // The width of the linear layout will scale, and at least one + // child said it wanted to match our width. Set a flag + // indicating that we need to remeasure at least that view when + // we know our width. + matchWidth = true; + matchWidthLocally = true; + } + + final int margin = lp.leftMargin + lp.rightMargin; + final int measuredWidth = child.getMeasuredWidth() + margin; + maxWidth = Math.max(maxWidth, measuredWidth); + + allFillParent = allFillParent && lp.width == LayoutParams.FILL_PARENT; + if (lp.weight > 0) { + /* + * Widths of weighted Views are bogus if we end up + * remeasuring, so keep them separate. + */ + weightedMaxWidth = Math.max(weightedMaxWidth, + matchWidthLocally ? margin : measuredWidth); + } else { + alternativeMaxWidth = Math.max(alternativeMaxWidth, + matchWidthLocally ? margin : measuredWidth); + } + + i += getChildrenSkipCount(child, i); + } + + // Add in our padding + mTotalLength += mPaddingTop + mPaddingBottom; + + int heightSize = mTotalLength; + + // Check against our minimum height + heightSize = Math.max(heightSize, getSuggestedMinimumHeight()); + + // Reconcile our calculated size with the heightMeasureSpec + heightSize = resolveSize(heightSize, heightMeasureSpec); + + // Either expand children with weight to take up available space or + // shrink them if they extend beyond our current bounds + int delta = heightSize - mTotalLength; + if (delta != 0 && totalWeight > 0.0f) { + 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) { + continue; + } + + LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) child.getLayoutParams(); + + 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)); + } 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)); + } + } + + final int margin = lp.leftMargin + lp.rightMargin; + final int measuredWidth = child.getMeasuredWidth() + margin; + maxWidth = Math.max(maxWidth, measuredWidth); + + boolean matchWidthLocally = widthMode != MeasureSpec.EXACTLY && + lp.width == LayoutParams.FILL_PARENT; + + alternativeMaxWidth = Math.max(alternativeMaxWidth, + matchWidthLocally ? margin : measuredWidth); + + allFillParent = allFillParent && lp.width == LayoutParams.FILL_PARENT; + alternativeMaxWidth = Math.max(alternativeMaxWidth, + matchWidthLocally ? margin : measuredWidth); + + mTotalLength += child.getMeasuredHeight() + lp.topMargin + + lp.bottomMargin + getNextLocationOffset(child); + } + + // Add in our padding + mTotalLength += mPaddingTop + mPaddingBottom; + } else { + alternativeMaxWidth = Math.max(alternativeMaxWidth, + weightedMaxWidth); + } + + if (!allFillParent && widthMode != MeasureSpec.EXACTLY) { + maxWidth = alternativeMaxWidth; + } + + maxWidth += mPaddingLeft + mPaddingRight; + + // Check against our minimum width + maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth()); + + setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec), heightSize); + + if (matchWidth) { + forceUniformWidth(count, heightMeasureSpec); + } + } + + private void forceUniformWidth(int count, int heightMeasureSpec) { + // Pretend that the linear layout has an exact size. + int uniformMeasureSpec = MeasureSpec.makeMeasureSpec(getMeasuredWidth(), + MeasureSpec.EXACTLY); + for (int i = 0; i< count; ++i) { + final View child = getVirtualChildAt(i); + if (child.getVisibility() != GONE) { + LinearLayout.LayoutParams lp = ((LinearLayout.LayoutParams)child.getLayoutParams()); + + if (lp.width == LayoutParams.FILL_PARENT) { + // Temporarily force children to reuse their old measured height + // FIXME: this may not be right for something like wrapping text? + int oldHeight = lp.height; + lp.height = child.getMeasuredHeight(); + + // Remeasue with new dimensions + measureChildWithMargins(child, uniformMeasureSpec, 0, heightMeasureSpec, 0); + lp.height = oldHeight; + } + } + } + } + + /** + * Measures the children when the orientation of this LinearLayout is set + * to {@link #HORIZONTAL}. + * + * @param widthMeasureSpec Horizontal space requirements as imposed by the parent. + * @param heightMeasureSpec Vertical space requirements as imposed by the parent. + * + * @see #getOrientation() + * @see #setOrientation(int) + * @see #onMeasure(int, int) + */ + void measureHorizontal(int widthMeasureSpec, int heightMeasureSpec) { + mTotalLength = 0; + int maxHeight = 0; + int alternativeMaxHeight = 0; + int weightedMaxHeight = 0; + boolean allFillParent = true; + float totalWeight = 0; + + final int count = getVirtualChildCount(); + + final int widthMode = MeasureSpec.getMode(widthMeasureSpec); + final int heightMode = MeasureSpec.getMode(heightMeasureSpec); + + boolean matchHeight = false; + + if (mMaxAscent == null || mMaxDescent == null) { + mMaxAscent = new int[VERTICAL_GRAVITY_COUNT]; + mMaxDescent = new int[VERTICAL_GRAVITY_COUNT]; + } + + final int[] maxAscent = mMaxAscent; + final int[] maxDescent = mMaxDescent; + + maxAscent[0] = maxAscent[1] = maxAscent[2] = maxAscent[3] = -1; + maxDescent[0] = maxDescent[1] = maxDescent[2] = maxDescent[3] = -1; + + final boolean baselineAligned = mBaselineAligned; + + // See how wide everyone is. Also remember max height. + for (int i = 0; i < count; ++i) { + final View child = getVirtualChildAt(i); + + if (child == null) { + mTotalLength += measureNullChild(i); + continue; + } + + if (child.getVisibility() == GONE) { + i += getChildrenSkipCount(child, i); + continue; + } + + final LinearLayout.LayoutParams lp = (LinearLayout.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. + mTotalLength += lp.leftMargin + lp.rightMargin; + + // Baseline alignment requires to measure widgets to obtain the + // baseline offset (in particular for TextViews). + // The following defeats the optimization mentioned above. + // Allow the child to use as much space as it wants because we + // can shrink things later (and re-measure). + if (baselineAligned) { + final int freeSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); + child.measure(freeSpec, freeSpec); + } + } 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 = lp.width; + lp.width = LayoutParams.WRAP_CONTENT; + } + + // Determine how big this child would like to be. If this or + // 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, + heightMeasureSpec, 0); + + if (oldWidth != Integer.MIN_VALUE) { + lp.width = oldWidth; + } + + mTotalLength += child.getMeasuredWidth() + lp.leftMargin + + lp.rightMargin + getNextLocationOffset(child); + } + + boolean matchHeightLocally = false; + if (heightMode != MeasureSpec.EXACTLY && lp.height == LayoutParams.FILL_PARENT) { + // The height of the linear layout will scale, and at least one + // child said it wanted to match our height. Set a flag indicating that + // we need to remeasure at least that view when we know our height. + matchHeight = true; + matchHeightLocally = true; + } + + final int margin = lp.topMargin + lp.bottomMargin; + final int childHeight = child.getMeasuredHeight() + margin; + + if (baselineAligned) { + final int childBaseline = child.getBaseline(); + if (childBaseline != -1) { + // Translates the child's vertical gravity into an index + // in the range 0..VERTICAL_GRAVITY_COUNT + final int gravity = (lp.gravity < 0 ? mGravity : lp.gravity) + & Gravity.VERTICAL_GRAVITY_MASK; + final int index = ((gravity >> Gravity.AXIS_Y_SHIFT) + & ~Gravity.AXIS_SPECIFIED) >> 1; + + maxAscent[index] = Math.max(maxAscent[index], childBaseline); + maxDescent[index] = Math.max(maxDescent[index], childHeight - childBaseline); + } + } + + maxHeight = Math.max(maxHeight, childHeight); + + allFillParent = allFillParent && lp.height == LayoutParams.FILL_PARENT; + if (lp.weight > 0) { + /* + * Heights of weighted Views are bogus if we end up + * remeasuring, so keep them separate. + */ + weightedMaxHeight = Math.max(weightedMaxHeight, + matchHeightLocally ? margin : childHeight); + } else { + alternativeMaxHeight = Math.max(alternativeMaxHeight, + matchHeightLocally ? margin : childHeight); + } + + i += getChildrenSkipCount(child, i); + } + + // Check mMaxAscent[INDEX_TOP] first because it maps to Gravity.TOP, + // the most common case + if (maxAscent[INDEX_TOP] != -1 || + maxAscent[INDEX_CENTER_VERTICAL] != -1 || + maxAscent[INDEX_BOTTOM] != -1 || + maxAscent[INDEX_FILL] != -1) { + final int ascent = Math.max(maxAscent[INDEX_FILL], + Math.max(maxAscent[INDEX_CENTER_VERTICAL], + Math.max(maxAscent[INDEX_TOP], maxAscent[INDEX_BOTTOM]))); + final int descent = Math.max(maxDescent[INDEX_FILL], + Math.max(maxDescent[INDEX_CENTER_VERTICAL], + Math.max(maxDescent[INDEX_TOP], maxDescent[INDEX_BOTTOM]))); + maxHeight = Math.max(maxHeight, ascent + descent); + } + + // Add in our padding + mTotalLength += mPaddingLeft + mPaddingRight; + + int widthSize = mTotalLength; + + // Check against our minimum width + widthSize = Math.max(widthSize, getSuggestedMinimumWidth()); + + // Reconcile our calculated size with the widthMeasureSpec + widthSize = resolveSize(widthSize, widthMeasureSpec); + + // Either expand children with weight to take up available space or + // shrink them if they extend beyond our current bounds + int delta = widthSize - mTotalLength; + if (delta != 0 && totalWeight > 0.0f) { + 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; + maxHeight = -1; + + mTotalLength = 0; + + 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; + 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 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); + } + } + + mTotalLength += child.getMeasuredWidth() + lp.leftMargin + + lp.rightMargin + getNextLocationOffset(child); + + boolean matchHeightLocally = heightMode != MeasureSpec.EXACTLY && + lp.height == LayoutParams.FILL_PARENT; + + final int margin = lp.topMargin + lp .bottomMargin; + int childHeight = child.getMeasuredHeight() + margin; + maxHeight = Math.max(maxHeight, childHeight); + alternativeMaxHeight = Math.max(alternativeMaxHeight, + matchHeightLocally ? margin : childHeight); + + allFillParent = allFillParent && lp.height == LayoutParams.FILL_PARENT; + alternativeMaxHeight = Math.max(alternativeMaxHeight, + matchHeightLocally ? margin : childHeight); + + if (baselineAligned) { + final int childBaseline = child.getBaseline(); + if (childBaseline != -1) { + // Translates the child's vertical gravity into an index in the range 0..2 + final int gravity = (lp.gravity < 0 ? mGravity : lp.gravity) + & Gravity.VERTICAL_GRAVITY_MASK; + final int index = ((gravity >> Gravity.AXIS_Y_SHIFT) + & ~Gravity.AXIS_SPECIFIED) >> 1; + + maxAscent[index] = Math.max(maxAscent[index], childBaseline); + maxDescent[index] = Math.max(maxDescent[index], + childHeight - childBaseline); + } + } + } + + // Add in our padding + mTotalLength += mPaddingLeft + mPaddingRight; + + // Check mMaxAscent[INDEX_TOP] first because it maps to Gravity.TOP, + // the most common case + if (maxAscent[INDEX_TOP] != -1 || + maxAscent[INDEX_CENTER_VERTICAL] != -1 || + maxAscent[INDEX_BOTTOM] != -1 || + maxAscent[INDEX_FILL] != -1) { + final int ascent = Math.max(maxAscent[INDEX_FILL], + Math.max(maxAscent[INDEX_CENTER_VERTICAL], + Math.max(maxAscent[INDEX_TOP], maxAscent[INDEX_BOTTOM]))); + final int descent = Math.max(maxDescent[INDEX_FILL], + Math.max(maxDescent[INDEX_CENTER_VERTICAL], + Math.max(maxDescent[INDEX_TOP], maxDescent[INDEX_BOTTOM]))); + maxHeight = Math.max(maxHeight, ascent + descent); + } + } else { + alternativeMaxHeight = Math.max(alternativeMaxHeight, + weightedMaxHeight); + } + + if (!allFillParent && heightMode != MeasureSpec.EXACTLY) { + maxHeight = alternativeMaxHeight; + } + + maxHeight += mPaddingTop + mPaddingBottom; + + // Check against our minimum height + maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight()); + + setMeasuredDimension(widthSize, resolveSize(maxHeight, heightMeasureSpec)); + + if (matchHeight) { + forceUniformHeight(count, widthMeasureSpec); + } + } + + private void forceUniformHeight(int count, int widthMeasureSpec) { + // Pretend that the linear layout has an exact size. This is the measured height of + // ourselves. The measured height should be the max height of the children, changed + // to accomodate the heightMesureSpec from the parent + int uniformMeasureSpec = MeasureSpec.makeMeasureSpec(getMeasuredHeight(), + MeasureSpec.EXACTLY); + for (int i = 0; i < count; ++i) { + final View child = getVirtualChildAt(i); + if (child.getVisibility() != GONE) { + LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) child.getLayoutParams(); + + if (lp.height == LayoutParams.FILL_PARENT) { + // Temporarily force children to reuse their old measured width + // FIXME: this may not be right for something like wrapping text? + int oldWidth = lp.width; + lp.width = child.getMeasuredWidth(); + + // Remeasure with new dimensions + measureChildWithMargins(child, widthMeasureSpec, 0, uniformMeasureSpec, 0); + lp.width = oldWidth; + } + } + } + } + + /** + * <p>Returns the number of children to skip after measuring/laying out + * the specified child.</p> + * + * @param child the child after which we want to skip children + * @param index the index of the child after which we want to skip children + * @return the number of children to skip, 0 by default + */ + int getChildrenSkipCount(View child, int index) { + return 0; + } + + /** + * <p>Returns the size (width or height) that should be occupied by a null + * child.</p> + * + * @param childIndex the index of the null child + * @return the width or height of the child depending on the orientation + */ + int measureNullChild(int childIndex) { + return 0; + } + + /** + * <p>Measure the child according to the parent's measure specs. This + * method should be overriden by subclasses to force the sizing of + * children. This method is called by {@link #measureVertical(int, int)} and + * {@link #measureHorizontal(int, int)}.</p> + * + * @param child the child to measure + * @param childIndex the index of the child in this view + * @param widthMeasureSpec horizontal space requirements as imposed by the parent + * @param totalWidth extra space that has been used up by the parent horizontally + * @param heightMeasureSpec vertical space requirements as imposed by the parent + * @param totalHeight extra space that has been used up by the parent vertically + */ + void measureChildBeforeLayout(View child, int childIndex, + int widthMeasureSpec, int totalWidth, int heightMeasureSpec, + int totalHeight) { + measureChildWithMargins(child, widthMeasureSpec, totalWidth, + heightMeasureSpec, totalHeight); + } + + /** + * <p>Return the location offset of the specified child. This can be used + * by subclasses to change the location of a given widget.</p> + * + * @param child the child for which to obtain the location offset + * @return the location offset in pixels + */ + int getLocationOffset(View child) { + return 0; + } + + /** + * <p>Return the size offset of the next sibling of the specified child. + * This can be used by subclasses to change the location of the widget + * following <code>child</code>.</p> + * + * @param child the child whose next sibling will be moved + * @return the location offset of the next child in pixels + */ + int getNextLocationOffset(View child) { + return 0; + } + + @Override + protected void onLayout(boolean changed, int l, int t, int r, int b) { + if (mOrientation == VERTICAL) { + layoutVertical(); + } else { + layoutHorizontal(); + } + } + + /** + * Position the children during a layout pass if the orientation of this + * LinearLayout is set to {@link #VERTICAL}. + * + * @see #getOrientation() + * @see #setOrientation(int) + * @see #onLayout(boolean, int, int, int, int) + */ + void layoutVertical() { + final int paddingLeft = mPaddingLeft; + + int childTop = mPaddingTop; + int childLeft = paddingLeft; + + // Where right end of child should go + final int width = mRight - mLeft; + int childRight = width - mPaddingRight; + + // Space available for child + int childSpace = width - paddingLeft - mPaddingRight; + + final int count = getVirtualChildCount(); + + final int majorGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; + final int minorGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; + + if (majorGravity != Gravity.TOP) { + switch (majorGravity) { + case Gravity.BOTTOM: + childTop = mBottom - mTop - mPaddingBottom - mTotalLength; + break; + + case Gravity.CENTER_VERTICAL: + childTop += ((mBottom - mTop - mPaddingTop - mPaddingBottom) - + mTotalLength) / 2; + break; + } + + } + + for (int i = 0; i < count; i++) { + final View child = getVirtualChildAt(i); + if (child == null) { + childTop += measureNullChild(i); + } else if (child.getVisibility() != GONE) { + final int childWidth = child.getMeasuredWidth(); + final int childHeight = child.getMeasuredHeight(); + + final LinearLayout.LayoutParams lp = + (LinearLayout.LayoutParams) child.getLayoutParams(); + + int gravity = lp.gravity; + if (gravity < 0) { + gravity = minorGravity; + } + + switch (gravity & Gravity.HORIZONTAL_GRAVITY_MASK) { + case Gravity.LEFT: + childLeft = paddingLeft + lp.leftMargin; + break; + + case Gravity.CENTER_HORIZONTAL: + childLeft = paddingLeft + ((childSpace - childWidth) / 2) + + lp.leftMargin - lp.rightMargin; + break; + + case Gravity.RIGHT: + childLeft = childRight - childWidth - lp.rightMargin; + break; + } + + + childTop += lp.topMargin; + setChildFrame(child, childLeft, childTop + getLocationOffset(child), + childWidth, childHeight); + childTop += childHeight + lp.bottomMargin + getNextLocationOffset(child); + + i += getChildrenSkipCount(child, i); + } + } + } + + /** + * Position the children during a layout pass if the orientation of this + * LinearLayout is set to {@link #HORIZONTAL}. + * + * @see #getOrientation() + * @see #setOrientation(int) + * @see #onLayout(boolean, int, int, int, int) + */ + void layoutHorizontal() { + final int paddingTop = mPaddingTop; + + int childTop = paddingTop; + int childLeft = mPaddingLeft; + + // Where bottom of child should go + final int height = mBottom - mTop; + int childBottom = height - mPaddingBottom; + + // Space available for child + int childSpace = height - paddingTop - mPaddingBottom; + + final int count = getVirtualChildCount(); + + final int majorGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; + final int minorGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; + + final boolean baselineAligned = mBaselineAligned; + + final int[] maxAscent = mMaxAscent; + final int[] maxDescent = mMaxDescent; + + if (majorGravity != Gravity.LEFT) { + switch (majorGravity) { + case Gravity.RIGHT: + childLeft = mRight - mLeft - mPaddingRight - mTotalLength; + break; + + case Gravity.CENTER_HORIZONTAL: + childLeft += ((mRight - mLeft - mPaddingLeft - mPaddingRight) - + mTotalLength) / 2; + break; + } + } + + for (int i = 0; i < count; i++) { + final View child = getVirtualChildAt(i); + + if (child == null) { + childLeft += measureNullChild(i); + } else if (child.getVisibility() != GONE) { + final int childWidth = child.getMeasuredWidth(); + final int childHeight = child.getMeasuredHeight(); + int childBaseline = -1; + + final LinearLayout.LayoutParams lp = + (LinearLayout.LayoutParams) child.getLayoutParams(); + + if (baselineAligned && lp.height != LayoutParams.FILL_PARENT) { + childBaseline = child.getBaseline(); + } + + int gravity = lp.gravity; + if (gravity < 0) { + gravity = minorGravity; + } + + switch (gravity & Gravity.VERTICAL_GRAVITY_MASK) { + case Gravity.TOP: + childTop = paddingTop + lp.topMargin; + if (childBaseline != -1) { + childTop += maxAscent[INDEX_TOP] - childBaseline; + } + break; + + case Gravity.CENTER_VERTICAL: + // Removed support for baselign alignment when layout_gravity or + // gravity == center_vertical. See bug #1038483. + // Keep the code around if we need to re-enable this feature + // if (childBaseline != -1) { + // // Align baselines vertically only if the child is smaller than us + // if (childSpace - childHeight > 0) { + // childTop = paddingTop + (childSpace / 2) - childBaseline; + // } else { + // childTop = paddingTop + (childSpace - childHeight) / 2; + // } + // } else { + childTop = paddingTop + ((childSpace - childHeight) / 2) + + lp.topMargin - lp.bottomMargin; + break; + + case Gravity.BOTTOM: + childTop = childBottom - childHeight - lp.bottomMargin; + if (childBaseline != -1) { + int descent = child.getMeasuredHeight() - childBaseline; + childTop -= (maxDescent[INDEX_BOTTOM] - descent); + } + break; + } + + childLeft += lp.leftMargin; + setChildFrame(child, childLeft + getLocationOffset(child), childTop, + childWidth, childHeight); + childLeft += childWidth + lp.rightMargin + + getNextLocationOffset(child); + + i += getChildrenSkipCount(child, i); + } + } + } + + private void setChildFrame(View child, int left, int top, int width, int height) { + child.layout(left, top, left + width, top + height); + } + + /** + * Should the layout be a column or a row. + * @param orientation Pass HORIZONTAL or VERTICAL. Default + * value is HORIZONTAL. + * + * @attr ref android.R.styleable#LinearLayout_orientation + */ + public void setOrientation(int orientation) { + if (mOrientation != orientation) { + mOrientation = orientation; + requestLayout(); + } + } + + /** + * Returns the current orientation. + * + * @return either {@link #HORIZONTAL} or {@link #VERTICAL} + */ + public int getOrientation() { + return mOrientation; + } + + /** + * Describes how the child views are positioned. Defaults to GRAVITY_TOP. If + * this layout has a VERTICAL orientation, this controls where all the child + * views are placed if there is extra vertical space. If this layout has a + * HORIZONTAL orientation, this controls the alignment of the children. + * + * @param gravity See {@link android.view.Gravity} + * + * @attr ref android.R.styleable#LinearLayout_gravity + */ + public void setGravity(int gravity) { + if (mGravity != gravity) { + if ((gravity & Gravity.HORIZONTAL_GRAVITY_MASK) == 0) { + gravity |= Gravity.LEFT; + } + + if ((gravity & Gravity.VERTICAL_GRAVITY_MASK) == 0) { + gravity |= Gravity.TOP; + } + + mGravity = gravity; + requestLayout(); + } + } + + public void setHorizontalGravity(int horizontalGravity) { + final int gravity = horizontalGravity & Gravity.HORIZONTAL_GRAVITY_MASK; + if ((mGravity & Gravity.HORIZONTAL_GRAVITY_MASK) != gravity) { + mGravity = (mGravity & ~Gravity.HORIZONTAL_GRAVITY_MASK) | gravity; + requestLayout(); + } + } + + public void setVerticalGravity(int verticalGravity) { + final int gravity = verticalGravity & Gravity.VERTICAL_GRAVITY_MASK; + if ((mGravity & Gravity.VERTICAL_GRAVITY_MASK) != gravity) { + mGravity = (mGravity & ~Gravity.VERTICAL_GRAVITY_MASK) | gravity; + requestLayout(); + } + } + + @Override + public LayoutParams generateLayoutParams(AttributeSet attrs) { + return new LinearLayout.LayoutParams(getContext(), attrs); + } + + /** + * 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#WRAP_CONTENT} + * when the layout's orientation is {@link #VERTICAL}. When the orientation is + * {@link #HORIZONTAL}, the width is set to {@link LayoutParams#WRAP_CONTENT} + * and the height to {@link LayoutParams#WRAP_CONTENT}. + */ + @Override + protected LayoutParams generateDefaultLayoutParams() { + if (mOrientation == HORIZONTAL) { + return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); + } else if (mOrientation == VERTICAL) { + return new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT); + } + return null; + } + + @Override + protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) { + return new LayoutParams(p); + } + + + // Override to allow type-checking of LayoutParams. + @Override + protected boolean checkLayoutParams(ViewGroup.LayoutParams p) { + return p instanceof LinearLayout.LayoutParams; + } + + /** + * Per-child layout information associated with ViewLinearLayout. + * + * @attr ref android.R.styleable#LinearLayout_Layout_layout_weight + * @attr ref android.R.styleable#LinearLayout_Layout_layout_gravity + */ + public static class LayoutParams extends ViewGroup.MarginLayoutParams { + /** + * Indicates how much of the extra space in the LinearLayout will be + * allocated to the view associated with these LayoutParams. Specify + * 0 if the view should not be stretched. Otherwise the extra pixels + * will be pro-rated among all views whose weight is greater than 0. + */ + @ViewDebug.ExportedProperty + public float weight; + + /** + * Gravity for the view associated with these LayoutParams. + * + * @see android.view.Gravity + */ + @ViewDebug.ExportedProperty(mapping = { + @ViewDebug.IntToString(from = -1, to = "NONE"), + @ViewDebug.IntToString(from = Gravity.NO_GRAVITY, to = "NONE"), + @ViewDebug.IntToString(from = Gravity.TOP, to = "TOP"), + @ViewDebug.IntToString(from = Gravity.BOTTOM, to = "BOTTOM"), + @ViewDebug.IntToString(from = Gravity.LEFT, to = "LEFT"), + @ViewDebug.IntToString(from = Gravity.RIGHT, to = "RIGHT"), + @ViewDebug.IntToString(from = Gravity.CENTER_VERTICAL, to = "CENTER_VERTICAL"), + @ViewDebug.IntToString(from = Gravity.FILL_VERTICAL, to = "FILL_VERTICAL"), + @ViewDebug.IntToString(from = Gravity.CENTER_HORIZONTAL, to = "CENTER_HORIZONTAL"), + @ViewDebug.IntToString(from = Gravity.FILL_HORIZONTAL, to = "FILL_HORIZONTAL"), + @ViewDebug.IntToString(from = Gravity.CENTER, to = "CENTER"), + @ViewDebug.IntToString(from = Gravity.FILL, to = "FILL") + }) + public int gravity = -1; + + /** + * {@inheritDoc} + */ + public LayoutParams(Context c, AttributeSet attrs) { + super(c, attrs); + TypedArray a = + c.obtainStyledAttributes(attrs, com.android.internal.R.styleable.LinearLayout_Layout); + + weight = a.getFloat(com.android.internal.R.styleable.LinearLayout_Layout_layout_weight, 0); + gravity = a.getInt(com.android.internal.R.styleable.LinearLayout_Layout_layout_gravity, -1); + + a.recycle(); + } + + /** + * {@inheritDoc} + */ + public LayoutParams(int width, int height) { + super(width, height); + weight = 0; + } + + /** + * 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 weight the weight + */ + public LayoutParams(int width, int height, float weight) { + super(width, height); + this.weight = weight; + } + + /** + * {@inheritDoc} + */ + public LayoutParams(ViewGroup.LayoutParams p) { + super(p); + } + + /** + * {@inheritDoc} + */ + public LayoutParams(MarginLayoutParams source) { + super(source); + } + + @Override + public String debug(String output) { + return output + "LinearLayout.LayoutParams={width=" + sizeToString(width) + + ", height=" + sizeToString(height) + " weight=" + weight + "}"; + } + } +} |