Java Code Examples for androidx.core.view.ViewCompat#getLayoutDirection()

private int calculateScrollXForTab(int position, float positionOffset) {
  if (mode == MODE_SCROLLABLE || mode == MODE_AUTO) {
    final View selectedChild = slidingTabIndicator.getChildAt(position);
    final View nextChild =
        position + 1 < slidingTabIndicator.getChildCount()
            ? slidingTabIndicator.getChildAt(position + 1)
            : null;
    final int selectedWidth = selectedChild != null ? selectedChild.getWidth() : 0;
    final int nextWidth = nextChild != null ? nextChild.getWidth() : 0;

    // base scroll amount: places center of tab in center of parent
    int scrollBase = selectedChild.getLeft() + (selectedWidth / 2) - (getWidth() / 2);
    // offset amount: fraction of the distance between centers of tabs
    int scrollOffset = (int) ((selectedWidth + nextWidth) * 0.5f * positionOffset);

    return (ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_LTR)
        ? scrollBase + scrollOffset
        : scrollBase - scrollOffset;
  }
  return 0;
}
 

@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
    final int count = getChildCount();
    final int width = right - left;
    final int height = bottom - top;
    //只支持top、bottom的padding
    final int padding_top = getPaddingTop();
    final int padding_bottom = getPaddingBottom();
    int used = 0;

    for (int i = 0; i < count; i++) {
        final View child = getChildAt(i);
        if (child.getVisibility() == GONE) {
            continue;
        }
        if (ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL) {
            child.layout(width - used - child.getMeasuredWidth(), padding_top, width - used, height - padding_bottom);
        } else {
            child.layout(used, padding_top, child.getMeasuredWidth() + used, height - padding_bottom);
        }
        used += child.getMeasuredWidth();
    }
}
 

void onMeasure(int measuredWidth, int measuredHeight) {
  if (clickableForegroundDrawable != null) {
    int left = measuredWidth - checkedIconMargin - checkedIconSize;
    int bottom = measuredHeight - checkedIconMargin - checkedIconSize;
    boolean isPreLollipop = VERSION.SDK_INT < VERSION_CODES.LOLLIPOP;
    if (isPreLollipop || materialCardView.getUseCompatPadding()) {
      bottom -= (int) Math.ceil(2f * calculateVerticalBackgroundPadding());
      left -= (int) Math.ceil(2f * calculateHorizontalBackgroundPadding());
    }

    int right = checkedIconMargin;
    if (ViewCompat.getLayoutDirection(materialCardView) == ViewCompat.LAYOUT_DIRECTION_RTL) {
      // swap left and right
      int tmp = right;
      right = left;
      left = tmp;
    }

    clickableForegroundDrawable.setLayerInset(
        CHECKED_ICON_LAYER_INDEX, left, checkedIconMargin /* top */, right, bottom);
  }
}
 

@Override
protected void onDraw(final Canvas canvas) {
    super.onDraw(canvas);
    final int layoutDirection = ViewCompat.getLayoutDirection(this);
    final int width = getWidth();
    final int height = getHeight();
    final float halfHeight = height / 2.0f;
    final Path path = mIndicatorPath;
    path.rewind();
    if (layoutDirection == ViewCompat.LAYOUT_DIRECTION_RTL) {
        // Left arrow
        path.moveTo(width, 0.0f);
        path.lineTo(0.0f, halfHeight);
        path.lineTo(width, height);
    } else { // LAYOUT_DIRECTION_LTR
        // Right arrow
        path.moveTo(0.0f, 0.0f);
        path.lineTo(width, halfHeight);
        path.lineTo(0.0f, height);
    }
    path.close();
    final int[] stateSet = getDrawableState();
    final int color = mIndicatorColor.getColorForState(stateSet, 0);
    mIndicatorPaint.setColor(color);
    canvas.drawPath(path, mIndicatorPaint);
}
 

@Test
public void testDismissViaSwipeRtl() throws Throwable {
  onView(withId(R.id.col)).perform(setLayoutDirection(ViewCompat.LAYOUT_DIRECTION_RTL));
  if (ViewCompat.getLayoutDirection(coordinatorLayout) == ViewCompat.LAYOUT_DIRECTION_RTL) {
    // On devices that support RTL layout, the start-to-end dismiss swipe is done
    // with swipeLeft() action
    verifyDismissCallback(
        onView(isAssignableFrom(Snackbar.SnackbarLayout.class)),
        swipeLeft(),
        null,
        Snackbar.LENGTH_INDEFINITE,
        Snackbar.Callback.DISMISS_EVENT_SWIPE);
  }
}
 

private boolean calculateIsRtl(CharSequence text) {
    final boolean defaultIsRtl = ViewCompat.getLayoutDirection(mView)
            == ViewCompat.LAYOUT_DIRECTION_RTL;
    return (defaultIsRtl
            ? TextDirectionHeuristicsCompat.FIRSTSTRONG_RTL
            : TextDirectionHeuristicsCompat.FIRSTSTRONG_LTR).isRtl(text, 0, text.length());
}
 

/**
 * Show a toast message with the hex color code below the view.
 */
public void showHint() {
  final int[] screenPos = new int[2];
  final Rect displayFrame = new Rect();
  getLocationOnScreen(screenPos);
  getWindowVisibleDisplayFrame(displayFrame);
  final Context context = getContext();
  final int width = getWidth();
  final int height = getHeight();
  final int midy = screenPos[1] + height / 2;
  int referenceX = screenPos[0] + width / 2;
  if (ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_LTR) {
    final int screenWidth = context.getResources().getDisplayMetrics().widthPixels;
    referenceX = screenWidth - referenceX; // mirror
  }
  StringBuilder hint = new StringBuilder("#");
  if (Color.alpha(color) != 255) {
    hint.append(Integer.toHexString(color).toUpperCase(Locale.ENGLISH));
  } else {
    hint.append(String.format("%06X", 0xFFFFFF & color).toUpperCase(Locale.ENGLISH));
  }
  Toast cheatSheet = Toast.makeText(context, hint.toString(), Toast.LENGTH_SHORT);
  if (midy < displayFrame.height()) {
    // Show along the top; follow action buttons
    cheatSheet.setGravity(Gravity.TOP | GravityCompat.END, referenceX, screenPos[1] + height - displayFrame.top);
  } else {
    // Show along the bottom center
    cheatSheet.setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL, 0, height);
  }
  cheatSheet.show();
}
 

default void setMarginEnd(int margin) {
    View view = (View) this;
    ViewGroup.LayoutParams params = view.getLayoutParams();
    if (!(params instanceof ViewGroup.MarginLayoutParams))
        throw new IllegalStateException("Invalid layoutParams. Unable to set margin.");
    ViewGroup.MarginLayoutParams layoutParams = (ViewGroup.MarginLayoutParams) params;
    int layoutDirection = ViewCompat.getLayoutDirection(view);
    if (layoutDirection == ViewCompat.LAYOUT_DIRECTION_LTR) {
        layoutParams.setMargins(layoutParams.leftMargin, layoutParams.topMargin, margin, layoutParams.bottomMargin);
    } else {
        layoutParams.setMargins(margin, layoutParams.topMargin, layoutParams.rightMargin, layoutParams.bottomMargin);
    }
    view.setLayoutParams(layoutParams);
}
 

private int getWidthAdjustment() {
    int width = recordButtonFab.getWidth() / 4;
    return ViewCompat.getLayoutDirection(recordButtonFab) == ViewCompat.LAYOUT_DIRECTION_LTR ? -width : width;
}
 

private void calculateCenterAndBounds(
    @NonNull Context context, @NonNull Rect anchorRect, @NonNull View anchorView) {
  switch (savedState.badgeGravity) {
    case BOTTOM_END:
    case BOTTOM_START:
      badgeCenterY = anchorRect.bottom - savedState.verticalOffset;
      break;
    case TOP_END:
    case TOP_START:
    default:
      badgeCenterY = anchorRect.top + savedState.verticalOffset;
      break;
  }

  if (getNumber() <= MAX_CIRCULAR_BADGE_NUMBER_COUNT) {
    cornerRadius = !hasNumber() ? badgeRadius : badgeWithTextRadius;
    halfBadgeHeight = cornerRadius;
    halfBadgeWidth = cornerRadius;
  } else {
    cornerRadius = badgeWithTextRadius;
    halfBadgeHeight = cornerRadius;
    String badgeText = getBadgeText();
    halfBadgeWidth = textDrawableHelper.getTextWidth(badgeText) / 2f + badgeWidePadding;
  }

  int inset =
      context
          .getResources()
          .getDimensionPixelSize(
              hasNumber()
                  ? R.dimen.mtrl_badge_text_horizontal_edge_offset
                  : R.dimen.mtrl_badge_horizontal_edge_offset);
  // Update the centerX based on the badge width and 'inset' from start or end boundary of anchor.
  switch (savedState.badgeGravity) {
    case BOTTOM_START:
    case TOP_START:
      badgeCenterX =
          ViewCompat.getLayoutDirection(anchorView) == View.LAYOUT_DIRECTION_LTR
              ? anchorRect.left - halfBadgeWidth + inset + savedState.horizontalOffset
              : anchorRect.right + halfBadgeWidth - inset - savedState.horizontalOffset;
      break;
    case BOTTOM_END:
    case TOP_END:
    default:
      badgeCenterX =
          ViewCompat.getLayoutDirection(anchorView) == View.LAYOUT_DIRECTION_LTR
              ? anchorRect.right + halfBadgeWidth - inset - savedState.horizontalOffset
              : anchorRect.left - halfBadgeWidth + inset + savedState.horizontalOffset;
      break;
  }
}
 

@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
private boolean isRtl() {
    return ViewCompat.getLayoutDirection(this) == View.LAYOUT_DIRECTION_RTL;
}
 

public static int getLeftMargin(@NonNull View view) {
  if (ViewCompat.getLayoutDirection(view) == ViewCompat.LAYOUT_DIRECTION_LTR) {
    return ((ViewGroup.MarginLayoutParams) view.getLayoutParams()).leftMargin;
  }
  return ((ViewGroup.MarginLayoutParams) view.getLayoutParams()).rightMargin;
}
 

private boolean isLayoutRtl() {
    return ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL;
}
 

private boolean isLayoutRtl() {
    return ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL;
}
 

private boolean isLayoutRTL() {
  return ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL;
}
 

private boolean isRTL() {
    return ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL;
}
 

@Override
protected void onLayout(boolean sizeChanged, int left, int top, int right, int bottom) {
  if (getChildCount() == 0) {
    // Do not re-layout when there are no children.
    rowCount = 0;
    return;
  }
  rowCount = 1;

  boolean isRtl = ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL;
  int paddingStart = isRtl ? getPaddingRight() : getPaddingLeft();
  int paddingEnd = isRtl ? getPaddingLeft() : getPaddingRight();
  int childStart = paddingStart;
  int childTop = getPaddingTop();
  int childBottom = childTop;
  int childEnd;

  final int maxChildEnd = right - left - paddingEnd;

  for (int i = 0; i < getChildCount(); i++) {
    View child = getChildAt(i);

    if (child.getVisibility() == View.GONE) {
      child.setTag(R.id.row_index_key, -1);
      continue;
    }

    LayoutParams lp = child.getLayoutParams();
    int startMargin = 0;
    int endMargin = 0;
    if (lp instanceof MarginLayoutParams) {
      MarginLayoutParams marginLp = (MarginLayoutParams) lp;
      startMargin = MarginLayoutParamsCompat.getMarginStart(marginLp);
      endMargin = MarginLayoutParamsCompat.getMarginEnd(marginLp);
    }

    childEnd = childStart + startMargin + child.getMeasuredWidth();

    if (!singleLine && (childEnd > maxChildEnd)) {
      childStart = paddingStart;
      childTop = childBottom + lineSpacing;
      rowCount++;
    }
    child.setTag(R.id.row_index_key, rowCount - 1);

    childEnd = childStart + startMargin + child.getMeasuredWidth();
    childBottom = childTop + child.getMeasuredHeight();

    if (isRtl) {
      child.layout(
          maxChildEnd - childEnd, childTop, maxChildEnd - childStart - startMargin, childBottom);
    } else {
      child.layout(childStart + startMargin, childTop, childEnd, childBottom);
    }

    childStart += (startMargin + endMargin + child.getMeasuredWidth()) + itemSpacing;
  }
}
 

private float getXOffset(float x) {
  return ViewCompat.getLayoutDirection(recordButtonFab) == ViewCompat.LAYOUT_DIRECTION_LTR ?
      -Math.max(0, this.startPositionX - x) : Math.max(0, x - this.startPositionX);
}
 

public static boolean isLayoutRtl(View view) {
  return ViewCompat.getLayoutDirection(view) == ViewCompat.LAYOUT_DIRECTION_RTL;
}
 

public static boolean isRTL(View view) {
    return ViewCompat.getLayoutDirection(view) == ViewCompat.LAYOUT_DIRECTION_RTL;
}