List of usage examples for android.view Gravity AXIS_Y_SHIFT
int AXIS_Y_SHIFT
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From source file:android.support.v7.widget.LinearLayoutCompat.java
/** * Measures the children when the orientation of this LinearLayout is set * to {@link #HORIZONTAL}./* w w w . j ava 2 s. co m*/ * * @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 childState = 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; boolean skippedMeasure = 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; final boolean useLargestChild = mUseLargestChild; final boolean isExactly = widthMode == MeasureSpec.EXACTLY; int largestChildWidth = Integer.MIN_VALUE; // 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; } if (hasDividerBeforeChildAt(i)) { mTotalLength += mDividerWidth; } final LinearLayoutCompat.LayoutParams lp = (LinearLayoutCompat.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. if (isExactly) { mTotalLength += lp.leftMargin + lp.rightMargin; } else { final int totalLength = mTotalLength; mTotalLength = Math.max(totalLength, totalLength + 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 { 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; 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; } final int childWidth = child.getMeasuredWidth(); if (isExactly) { 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)); } if (useLargestChild) { largestChildWidth = Math.max(childWidth, largestChildWidth); } } boolean matchHeightLocally = false; if (heightMode != MeasureSpec.EXACTLY && lp.height == LayoutParams.MATCH_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; childState = ViewUtils.combineMeasuredStates(childState, ViewCompat.getMeasuredState(child)); 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.MATCH_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); } if (mTotalLength > 0 && hasDividerBeforeChildAt(count)) { mTotalLength += mDividerWidth; } // 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); } if (useLargestChild && (widthMode == MeasureSpec.AT_MOST || widthMode == MeasureSpec.UNSPECIFIED)) { mTotalLength = 0; 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 LinearLayoutCompat.LayoutParams lp = (LinearLayoutCompat.LayoutParams) child .getLayoutParams(); if (isExactly) { mTotalLength += largestChildWidth + lp.leftMargin + lp.rightMargin + getNextLocationOffset(child); } else { final int totalLength = mTotalLength; mTotalLength = Math.max(totalLength, totalLength + largestChildWidth + lp.leftMargin + lp.rightMargin + getNextLocationOffset(child)); } } } // Add in our padding mTotalLength += getPaddingLeft() + getPaddingRight(); int widthSize = mTotalLength; // Check against our minimum width widthSize = Math.max(widthSize, getSuggestedMinimumWidth()); // Reconcile our calculated size with the widthMeasureSpec int widthSizeAndState = ViewCompat.resolveSizeAndState(widthSize, widthMeasureSpec, 0); widthSize = widthSizeAndState & ViewCompat.MEASURED_SIZE_MASK; // 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; if (skippedMeasure || 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 LinearLayoutCompat.LayoutParams lp = (LinearLayoutCompat.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, getPaddingTop() + getPaddingBottom() + 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 may now not fit in horizontal dimension. childState = ViewUtils.combineMeasuredStates(childState, ViewCompat.getMeasuredState(child) & ViewCompat.MEASURED_STATE_MASK); } if (isExactly) { mTotalLength += child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin + getNextLocationOffset(child); } else { final int totalLength = mTotalLength; mTotalLength = Math.max(totalLength, totalLength + child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin + getNextLocationOffset(child)); } boolean matchHeightLocally = heightMode != MeasureSpec.EXACTLY && lp.height == LayoutParams.MATCH_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.MATCH_PARENT; 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 += getPaddingLeft() + getPaddingRight(); // TODO: Should we update widthSize with the new total length? // 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); // We have no limit, so make all weighted views as wide as the largest child. // Children will have already been measured once. if (useLargestChild && widthMode != MeasureSpec.EXACTLY) { for (int i = 0; i < count; i++) { final View child = getVirtualChildAt(i); if (child == null || child.getVisibility() == View.GONE) { continue; } final LinearLayoutCompat.LayoutParams lp = (LinearLayoutCompat.LayoutParams) child .getLayoutParams(); float childExtra = lp.weight; if (childExtra > 0) { child.measure(MeasureSpec.makeMeasureSpec(largestChildWidth, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(child.getMeasuredHeight(), MeasureSpec.EXACTLY)); } } } } if (!allFillParent && heightMode != MeasureSpec.EXACTLY) { maxHeight = alternativeMaxHeight; } maxHeight += getPaddingTop() + getPaddingBottom(); // Check against our minimum height maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight()); setMeasuredDimension(widthSizeAndState | (childState & ViewCompat.MEASURED_STATE_MASK), ViewCompat.resolveSizeAndState(maxHeight, heightMeasureSpec, (childState << ViewCompat.MEASURED_HEIGHT_STATE_SHIFT))); if (matchHeight) { forceUniformHeight(count, widthMeasureSpec); } }